Synthetic Oil vs. Natural Oil

[Matt Timion]

I just had my oil changed today and they put in synthetic oil. Instantly I noticed my RPMs were lower. Usually my car idles between 1200rpm and 1500rpm (I know this is high, but I havn't adjusted it yet) and now it is idling around 1000rpm.

Has anyone else noticed this when switching to synthetic? I know that there has been a debate on the benefits of switching to synthetic for years, but it seems to me to be a no-brainer.

I havn't noticed a mpg gain yet, as I've only driving about 10 miles since getting my oil changed, but the lower RPMs indicate that I WILL get a MPG gain from switching to synthetic.


What say you?

[nrgrebel]

I've always seen noticeable increases in gas mileage running synthetics. All of my vehicles have synthetic lubricants from bumper to bumper. However... one would think since your rpms decreased your mileage would too! Ideally you should see higher rpms at the same throttle position and fuel flow. In the past I've often had to adjust idle speeds down because the use of synthetics would increase my idle rpms. Also, all synthetics are NOT the same. Some major brand names at one time were pretty decent. They have since reformulated to lower grade hydro cracked base stocks (though the kept prices the same as when they had the higher quality POA's).

[SVOboy]

Interesting idea nrgrebel, I've never heard this before, I'd like to do some research on it, as it makes sense, I think. If you're at a higher rpm for game energy output would you not be making more power for the same fuel flow?

In any case, Matt, what viscosity of oil did they put it, not 0w30 was it? ^_^, I wanna put that in my car next time, but right now it's idling at 750, just so you get and idea.

[Matt Timion]

Interesting idea nrgrebel, I've never heard this before, I'd like to do some research on it, as it makes sense, I think. If you're at a higher rpm for game energy output would you not be making more power for the same fuel flow?

In any case, Matt, what viscosity of oil did they put it, not 0w30 was it? ^_^, I wanna put that in my car next time, but right now it's idling at 750, just so you get and idea.

They put 10w30 in my car. I might put 0w30 in my engine after the swap, but I don't want to do anything too drastic until after the engine is swapped.

I guess this weekend will be a good measure of my gas mileage. I'm driving from Salt Lake City, UT to Las Vegas, NV tomorrow morning. This will be my base mileage, and then on the way back I'll put acetone in the gas tank and measure my mileage on the way up. I'll also monitor RPM and speed in the event that going uphill/downhill have any effect on the gas mileage.

[SVOboy]

Don't forget to pull your negative cable or hazard fuse for a few minutes to reset the ecu after you have let the acetone mix in a little bit.

[MetroMPG]

my understanding of synthetic vs mineral is that you'll notice an efficiency improvement at low temps only. synthetic has better viscosity stability and pourability than equivalent weight mineral oils at low temperatures (mineral gets much thicker).

so the only time the engine is running more efficiently on synthetics is from start-up until it reaches normal operating temperature. once warmed, there's no difference.

have a read through mobiloil.com - you'll see they don't promise efficiency gains. just improved performance under "extreme" conditions. if they could promise gains in mpg across the board, you can be sure it would be all over their marketing.

[rh77]

Since the molecule size of synthetic oil is much smaller than mineral-based oils, older/higher mileage engines tend to leak or burn synthetic pretty quickly as it creeps between old gaskets, seals, and rings. Just keep an eye on the level over time...

RH77

[jamescartagena]

Here is an email that I received from an Amsoil dealer and member of Society of Automotive Engineers. I'm partial to Amsoil as I've tested it and use it in both my vehicles. I've noticed a solid 1 mpg gain in my F150 pickup.

Thanks for the update James. AMSOIL Series 2000 0W-30 Severe Service is one of the very best and is a 35,000 mile/1-year oil. Change the AMSOL Super Duty oil filter every 12,500 miles/6-months (note that this fall AMSOIL has 25,000 mile oil filters coming out, an exclusive industry first patented nanofiber technology). If you do not put 35,000 miles per year on then the 5W-30 (ASL) or the 10W-30 (ATM) are also excellent choices and both are 25,000 mile/1-year lubricants. All AMSOIL Synthetic Lubricants meet and far exceed all manufacturer specifications as well as API Specifications.

AMSOIL Series 3000 5W-30 HDD is the most advanced chemistry product AMSOIL offers and is also a 25,000 mile/1-year oil in non-commercial gas engine passenger cars and light truck applications. It has the beefiest additive package of all AMSOIL motor oils and resists oil breakdown from heat, blow-by chemicals and oxygen up to 10 times longer than conventional oils. It is also an excellent severe duty fleet type oil for applications such as police and delivery fleets.

the AMSOIL Series 2000 0W-30 Severe Service is a racing oil and of a different chemistry than the 10W-30 and 5W-30. I have been a Ford Engineer and Lubrication Specialist for over 20 years and we often use the 0W-30 in the 800 Hp Ford/Roush Nascars as it has a shear strength better than most 50W oils and transfers heat more efficiently than heavier oils. Only about 60% of the engine cooling is done by the coolant and the rest is done by the oil via heat transfer. The 10W-30 and 5W-30 would not be good choices for racing. The 5W-30 ASL product code and 10W-30 ATM are both 25,000 mile/1-year oils where the 0W-30 is a 35,000 mile/1-year oil. The 4-ball wear test is also run at a different load, temp and RPM than the other 2 products so they cannnot be compared in that area. The 0W-30 does not thin out to a 0W as it gets hot. It stays a 30W just like the 10W-30 and the 5W-30. They are ALL 30 weight oils and each one can be beneficial in a specific application. The 10W-30 is a better oil under certain instances for higher mileage engines as it has a lower volatility. 10W-40 High Performance is a heavier duty oil for severe off road, towing and RV type use and is also a 25,000 mile/1-year oil.

I am here to help anytime and if you decide to become a dealer please let me know.

Best Regards,
ÂÂ*
Dave Mann
Lubrication Specialist - Truck/Automotive Engineer
Society of Automotive Engineers Professional Member
Performance Oil Technology, L.L.C.
www.performanceoiltechnology.com
1-888-879-1362
ÂÂ*
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Wolverine Lake, MI 48390
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[CosmicMC]

The debate about synthetics versus dino oil usually turns into a religious one rather than one based on facts. People hear some slick marketing somewhere and it gets stuck in their heads as the word of god. The fact is that synthetic oil has some properties that are technically superior to conventional motor oils. Another fact is that in most circumstances, those technical superiorities don't amount to much more than a tiny hill of beans when it comes to engine longevity and fuel efficiency, and they will probably cost you more money in the long run.

jamescartagena's post above removes a lot of credibility from this entire web site. He wants you to buy Amsoil and become an Amsoil dealer not because it's good for you or your car or your wallet but because it benefits his wallet. He's a salesman, and he's here because he doesn't want to pay for advertisements. It's unfortunate that the administration of gassavers.org allows someone to advertise for free on the site. Amsoil is a multi-level marketing scheme. You know the difference between a dead possum on the highway and a dead Amsoil salesman on the highway? There are swerve marks before the possum.

So let's use Amsoil synthetics as an example of how synthetics are mostly useless. This is an easy one. Amsoil says certain of their products are good for 25,000 miles or 1 year. That's for normal driving. For severe service it's 15,000 miles or 1 year. All of that depends on you using an Amsoil oil filter and changing it in 6 months or half the mileage interval. That oil costs $6.35 per quart, and the filters are $10-$12 each. A name-brand, high-quality conventional motor oil costs about $2.00 per quart, and you can get a high-quality oil filter for $5-$6. so Amsoil costs over 3x more than regular oil. OK, so let's say your car takes 4 quarts of oil, your driving doesn't fall into the severe service category, and you drive 12,500 miles per year.

Here's the scenario: You have a recent model GM car with the Oil Life Monitor system that calculates the remaining lifetime of your motor oil based on mileage, temperatures, engine RPMs, and other factors. You changed your oil with Havoline 10W-30 and a $5.00 AC-Delco oil filter one year ago and drove 11,000 miles, and the Oil Change light just illuminated on your dashboard. You do a used oil analysis on that used conventional oil at a cost of $20 and it shows that the oil was protecting your engine just fine when you drained it. So your oil change cost you a total of $13 and with the analysis $33.

If you had used Amsoil, you would have paid $25.40 for the 4 quarts of oil, plus another $20-$24 for two Amsoil filters, so without even doing the analysis, you have already paid $47 for an oil change instead of $13. You have the analysis done on the Amsoil oil and you find that it also was protecting your engine just fine. What have you gained by using Amsoil? Was it worth the 362% higher cost of Amsoil?

The days of 3000 mile oil changes are gone, but that's what Amsoil still quotes in their numbers, and the latest Oil Life Monitor system from GM will extend your oil change interval to 12,500 miles if you drive the car normally and not in severe service. GM wouldn't tell you to go 12,500 miles before getting an oil change if it was going to damage your engine because it would give them an even worse reputation for quality compared to the Japanese automakers. New engines and new engine oils are far, far better than they were even a few years ago, and as time goes on, Amsoil and synthetic oils in general become less and less relevant. They'll quote you all kinds of 4-ball wear tests and tons and tons of totally irrelevant facts and statistics. All you need to remember is this: When was the last time you heard of somebody who changed their oil regularly with ANY kind of oil having their engine die an early death because of lubrication problems? That's all that matters really, but Amsoil would like you to believe your car won't last as long with regular oil. Think for yourself about it. Have you ever heard of such a problem? By the time a car gets that many miles on it, so many other things would have broken and been replaced that the engine would be cheap by comparison.

Do yourself a favor and avoid Amsoil and other synthetic oils. Put the money you save in your vacation or retirement account, donate it to a worthy charity, or take your special someone out for dinner. Don't give it to an oil salesman for a mostly useless product.

[CosmicMC]

The "molecule size" of synthetic oil is not "much smaller" than mineral-based motor oils. The only difference is that synthetics have a more uniform size than mineral oils do. Synthetics are made from natural gas and some other things, not refined from crude oil. Refining is not a perfect process. Some heavier and some lighter things are left in there such as paraffin and benzene. Modern refining has reduced the level of those items to very, very small levels, and in fact some oils marketed as "synthetic" are really just mineral oils that have gone through extra refining steps. This might include some Amsoil products. Synthetics do not cause leaks and it doesn't creep between anything any more than mineral oil does. The additives in synthetic oils may harden or otherwise affect some older seals, and if those seals are already mechanically compromised in some way, leaks can happen where they weren't before, but the root cause is really the mechanical degradation of the engine and not the synthetic oil.

You don't need to avoid synthetics because of worries about leaks. Avoid them because they aren't worth 3x the price, the benefits in reality are negligible or zero, and the salesmen can be slimy, greedy, lying scumbags who pull all kinds of tricks to try and dupe you into buying their products.

[diamondlarry]

jamescartagena's post above removes a lot of credibility from this entire web site. He wants you to buy Amsoil and become an Amsoil dealer not because it's good for you or your car or your wallet but because it benefits his wallet. He's a salesman, and he's here because he doesn't want to pay for advertisements. It's unfortunate that the administration of gassavers.org allows someone to advertise for free on the site. Amsoil is a multi-level marketing scheme. You know the difference between a dead possum on the highway and a dead Amsoil salesman on the highway? There are swerve marks before the possum.

I don't think he said he was a salesman. Actually, what he said was,Here is an email that I received from an Amsoil dealer and member of Society of Automotive Engineers. I'm partial to Amsoil as I've tested it and use it in both my vehicles. I've noticed a solid 1 mpg gain in my F150 pickup.

He was asked by the other person to contact him if he ever wanted to become a dealer.I am here to help anytime and if you decide to become a dealer please let me know. I also use Amsoil in my car but am NOT a dealer for the very reason you stated about James' credibilty. If I were to become a dealer, my credibility would be lost to someones perception that I would be out to drain everyones wallet.

[Matt Timion]

jamescartagena's post above removes a lot of credibility from this entire web site. He wants you to buy Amsoil and become an Amsoil dealer not because it's good for you or your car or your wallet but because it benefits his wallet. He's a salesman, and he's here because he doesn't want to pay for advertisements. It's unfortunate that the administration of gassavers.org allows someone to advertise for free on the site. Amsoil is a multi-level marketing scheme. You know the difference between a dead possum on the highway and a dead Amsoil salesman on the highway? There are swerve marks before the possum.

Admin of Gassavers here...

Just so know you, i understand what you are saying, mostly. I've been leary of sythetic oil myself and have never actually seen evidence one way or another which will confirm the claims that synthetic oil gives better gas mileage. The manufacturers themselves rarely say this. While they may be behind the scenes whispering into people's ears that sythetic oil is the best oil for your car, they never do it publically.

This carries a lot of weight with me. In Carl Sagan's Demon Haunted World he pointed out that extra-ordinary claims require extra-ordinary proof (of course I'm paraphrasing, but you get my drift). Most of the synthetic oil companies avoid this by never making the claims in the first place.

Now adays, however, anyone can claim that their device improves fuel economy without it really affecting them directly. The makers of the Tornado have managed to sell their snake oil in name brand retail auto parts stores. The "Khaos Turbo Charger" managed to fool even the government of some countries. Remember though, extra-ordinary claims require extra-ordinary proof.

Which is the main reason this site was started. Not only is it a geeky hobby of mine, but it is also a place for people to get together and discuss the proofs behind fuel efficiency. I've read the message boards elsewhere and i've seen the websites selling the products.

I'm hoping that this website does not turn out to be like the other ones.

This site has something unique. People can actually call "bull****" when someone makes a claim. A free exchange of ideas allows for people to disagree and require proof. Does pissing in your gastank really help gas mileage? Prove it. Show me numbers.

I'm not sure if I mentioned this before but I have a degree in Psychology. I know all about how gullible the human animal is and I know all about how an experiment is supposed to be run. I excel at numbers and math and also know how to crunch the numbers if I need to. I also know what it's like to be in a society where free ideas and information are not only discouraged, but punished. I won't talk more about that in public, if you want to know what I'm talking about, feel free to send me a private message. The last thing that we want to do here is discourage people from posting what they know, or what they think is true. It allows everyone to be educated, edified, and in the end, as DiamondLarry as said in the past, we all win.

So as Administrator I will not delete a post simply because I don't know it to be true. I will also not be the one who asks for proof constantly. I think a group of people who really care about what we're trying to do here and who are sick of junk science, scams, and rips offs will collectively call "bull****" on each other. If you call bull**** on me and I really believe what I'm saying I will be delighted to prove it to you. I'll only get offended if I don't believe it myself.

So, you've called bull**** on sythetic oil. Now it's time for people to prove you wrong, if they can. I'm interested in the results as well.

[rh77]

I'm right there with you on this one, Matt. This board tries to maintain the highest integrity of the scientific process. Clean Data and Analysis. No butt-dynos here. Prove it legitimately. If a salesman comes on here, we can choose to ignore or test the product. I think we try to keep it friendly too...

RH77

[Compaq888]

you got to have proof is right. Like my mpg is true because I filled up and didn't make a number. I will tell you right now. I have used Mobil 1 before and I even drove in my sweet spot and it would never go over 29mpg for freeway ONLY. I now get 30mpg in the mix, that means city and freeway combined. I use royal rurple. I change it every 3k and use a nissan filter because it's better than a FRAM or Mobil filter. I have always used the same gas. Chevron or Shell. So you try to explain how I get 30mpg in the mix when before I got less than 29mpg on the freeway only. Everybody knows I replaced a bunch of parts to get this mpg, and when I got less than 29mpg I had a $485 maintenance where ALL the fluids were changed and all the small stuff was replaced. And I still got 29mpg. The only difference now is I use royal purple and my tires are pumped up 5psi from oem numbers on the door. Which is 32psi.

[CosmicMC]

Well Matt, I'm very happy to hear this. I expected to be banned. In case there is any confusion, you have it right, I call bull**** on synthetic oils and especially Amsoil. I appreciate your forward-thinking attitude.

Let me state for the record that I am not any kind of expert at anything but my job, and that has nothing to do with any kind of car technology or fluids or anything automotive-related whatsoever. I just read a lot and run various experiments on my own for my own amusement, plus I get a warm and tingly feeling from learning the truth, kind of like when you get a new 12-pack of underwear from a humongous retail store chain: Whether you admit it or not, you know you secretly pick those new skivvies out of the drawer in the morning before those crusty old ones because the new ones just feel better, and also because the elastic is still attached to the butt part. That's why I like to find the truth: Because those new Wal-Mart house brand 12 for $1.99 undies make perfect sense when you're in the store. Later on down the road, it's very possible you'll realize that you spend 2/3 of your day adjusting things by walking funny in public and that those undies may have been so affordable because they are forged from recycled fiberglass insulation. But you can still look forward to getting a different brand megapack of new undies and have another new-underwear nirvana experience next week. Anyway, the point is that even being proven wrong is a learning experience, and that's the new Sack O' Skivvies I so desperately crave.

When I think about "gassavers.org," I'm not sure whether that means the site is geared toward conservation of oil or conservation of cash. I am personally strongly biased toward conservation of cash, mostly because I'm not at all interested in helping some anonymous ******* 87-year-old oil company executive buy a bigger yacht and a diamond-encrusted collar for his 26-year-old wife Muffy's pet poodle. Most of the time, saving cash also means saving oil resources. Not always, though, so it's important to make the distinction.

Compaq888, I can't make any sense out of your post. One one side it sounds like you attribute your gas mileage gain to expensive purple oil. On the other side it sounds like you've done lots of other things to try and gain a few MPG, so you really can't point to the oil as the source of the gain. Either way, you're changing synthetic oil at a 3000 mile interval which is a huge waste of time and money. Any gas savings you have from doing that is more than wiped out by your oil change practices. What exactly are you trying to accomplish with your tweaking and tuning? Money savings? If that's the case, I think you could do much better by changing to conventional motor oil, which is recommended by Nissan by the way, and doing a used oil analysis to help you determine what interval would be both safe and also cost less money. Try Blackstone Labs or Dyson Oil Analysis or any one of the many oil analysis laboratories out there. It's typically $20. You could save that much on a single oil change by following their advice instead of making up an oil change schedule based on marketing and speculation. Before you do anything, though, decide exactly what it is you are trying to accomplish. Saving money? Saving oil resources? Just trying to get the highest MPG number possible at any cost so you can sound cool on a web site? So you get 1 MPG better. That's terrific, but what does that 1 MPG cost you? The oil is about 3 times as expensive. Do you make that up in the cost of gas? Is it really worth it??? To me, that's the question to be answered on gassavers.org. I'll offer whatever proof and hard data I can to help in those efforts.

[Matt Timion]

When I think about "gassavers.org," I'm not sure whether that means the site is geared toward conservation of oil or conservation of cash. I am personally strongly biased toward conservation of cash, mostly because I'm not at all interested in helping some anonymous ******* 87-year-old oil company executive buy a bigger yacht and a diamond-encrusted collar for his 26-year-old wife Muffy's pet poodle. Most of the time, saving cash also means saving oil resources. Not always, though, so it's important to make the distinction.

Excellent point. I've touched on this a few times, but not very securely. Originally my plan was to save money. The goal was to build a car that could get 50mpg for a fraction of the cost of buying a hybrid. That is still sort of my goal. The fact is, however, that from a purely monitary standpoint I'll never make the money back I've put into this car. I've purchased a new transmission, a new engine, I've painted it, bought new trim to make it look pretty, new seats, hardware for cruise control, new rims and tires (twice) and other little things that I can't even begin to add up. I've probably spent the value of the car in parts and repairs. Now it's a hobby more than anything else. My hobby is to get high gas mileage. That isn't much different than people dropping $400 on a carbon fiber hood so they can save 5lbs on their total weight. Actually, that is more wasteful than what I'm doing.

I will probably never break even. I work at home and drive a total of something like 5000-6000 miles a year in my car. That figure is with the road trips to Las Vegas twice a year. It's ridiculous how little I drive. It's about more than money though now. Part of my motivation is now about doing my part to be part of the solution and not part of the problem. If 25% of our population worked at home and had very fuel efficient cars then I guess we wouldn't have much of an oil crisis to worry about.

As for the website's purpose, it's up to the user. I really don't care if people are here to save money, help the enviroment, or just to reduce foreign dependance on oil. To me it's all the same in the end. If people with different agendas can get together for a common goal, then we all win.

Before you do anything, though, decide exactly what it is you are trying to accomplish. Saving money? Saving oil resources? Just trying to get the highest MPG number possible at any cost so you can sound cool on a web site? So you get 1 MPG better. That's terrific, but what does that 1 MPG cost you? The oil is about 3 times as expensive. Do you make that up in the cost of gas? Is it really worth it??? To me, that's the question to be answered on gassavers.org. I'll offer whatever proof and hard data I can to help in those efforts.

this is another one of my problems with sythetic oil. I looked online and saw it was $5/quart. I guess if you do your oil changes yourself you pretty much break even when compared to having the guy at Jiffy Lube do it for you. $20 vs. $20. Right now though $20 is 10 gallons of gasoline. I get 33 mpg (right now, at least). Is using the purple oil going to save me 330 miles worth of gas per oil change? if I change my oil every 3000 miles and get a 1mpg improvement, yes it will. but my engine also burns oil, so I'll end up putting more oil into the engine during the experiment. I also don't see the marginal benefit of doing something that makes me break even.

I'm blabbing now, but I hope you get my drift. I need to go eat lunch and put my new tires on my n600.

[n0rt0npr0]

I cannot prove Synthetics cause leaks. In 6 out of my last 6 vehicles I've visually encountered increased oil seepage AFTER I went from dino juice to synthetic. Didn't matter whether it was Royal Purple or Mobil One, after 500 miles of use, new spots of oil have occurred on my driveway. Mileage? I've made the switch as early as *edit* 20K to as late as 230K.
One advantage to synthetics I've found is a little better overall fuel mileage(went from 22mpg to 24mpg in one vehicle but generally 7% increase in economy)
I've done tests on dino oil, and I can't get dino oil to last longer than 8,000 miles in any 1988-1994 GM 60 degree V6 engine. My synthetics are lasting 25,000 miles by comparison. Using the same $6 filters too. Over three times the longevity there.
$13.50 for dino oil change
$32.00 for synthetic oil change

After 25,000 miles, I save $8 on the oil changes + the time involved to do them in my driveway + $431.22 worth of gas.
Well one more thing, I am not figuring the cost of "topping off" but as you can see with those gas savings, I wouldn't really need to.

So with 14 years of synthetic oil usage, I can conclude that synthetic oil use does lead to increased oil consumption but still significantly less overall than if you were to keep doing Dino oil changes every 8,000 miles.

We're here to contribute ways to make us less dependant on crude oil reserves, and this is just a small drop in the bucket but every drop counts.
~Will

[SVOboy]

I might as well chime in and say that I dunno much about this difference, but my family has always used full synthetics and none of the cars have leaked oil.

[n0rt0npr0]

*

[n0rt0npr0]

You should chime up and list ALL the models that have not leaked the oil. It will help guide me to my next vehicle choice in the future.

[SVOboy]

Current 1991 Honda CRX DX
Mom's current 1993 Toyota Camry DX (run synthetic for the full life of the vehicle)
Dad's BMW something something, dad's plymouth breeze (sucks anyway)

[CosmicMC]

So Will, do you have a long commute every day or do you take lots of long trips? How long do you go between filter changes?

I'm curious to see those used oil analyses. Please post them. I don't know what property of synthetic oils would give you a 7% fuel economy increase. Amsoil says "AMSOIL Synthetic 10W-30 Motor Oil is designed to maximize energy efficiency for improved fuel economy. Unlike conventional oils, its uniform molecular structure helps it flow more freely and reduce friction between metal surfaces. Anti-friction additives are included to further improve energy efficiency." The problems with that statement are that once the oil is up to operating temperature, it's a 30 weight oil, just as it says on the bottle, so it doesn't flow any better than any other 30 weight oil, plus every motor oil contains anti-friction additives. If Amsoil thought you could get a 7% increase in gas mileage and save $400, they would tell you that to try and sell more oil, but they don't make any such claims. They include all sorts of 4-ball wear tests and other useless marketing B.S., but they don't tell you that you can get much better gas mileage. That just doesn't add up. I don't believe the mileage numbers you've quoted have anything to do with synthetic oil for that reason.

Here is what Mobil 1 says:

"What's the overall benefit of Mobil 1 with SuperSyn Technology?
Mobil 1 with SuperSyn Technology exceeds the latest industry and OEM requirements. It is designed for vehicles under warranty and will provide protection for the maximum oil change interval recommended in your owner's manual or by your oil life sensor.

The overall goal for Mobil 1 has always been to protect your engine, even under the most severe conditions, such as cold starting temperatures, extreme high-temperature operations and high-load conditions. Mobil 1 has been formulated with a performance reserve to provide you the peace of mind that your engine is protected during these severe conditions. But Mobil 1 with SuperSyn is not just for extreme service. You can also realize Mobil 1's benefits of improved engine cleanliness and extended engine life under "normal" service."

Nothing at all in there about fuel economy increases. Why not? If it's so great for fuel economy, why aren't they advertising it? Royal Purple says up to a 5% fuel economy gain with no numbers to back it up. Maybe you should give them a testimonial?

[Compaq888]

Compaq888, I can't make any sense out of your post. One one side it sounds like you attribute your gas mileage gain to expensive purple oil. On the other side it sounds like you've done lots of other things to try and gain a few MPG, so you really can't point to the oil as the source of the gain. Either way, you're changing synthetic oil at a 3000 mile interval which is a huge waste of time and money. Any gas savings you have from doing that is more than wiped out by your oil change practices. What exactly are you trying to accomplish with your tweaking and tuning? Money savings? If that's the case, I think you could do much better by changing to conventional motor oil, which is recommended by Nissan by the way, and doing a used oil analysis to help you determine what interval would be both safe and also cost less money. Try Blackstone Labs or Dyson Oil Analysis or any one of the many oil analysis laboratories out there. It's typically $20. You could save that much on a single oil change by following their advice instead of making up an oil change schedule based on marketing and speculation. Before you do anything, though, decide exactly what it is you are trying to accomplish. Saving money? Saving oil resources? Just trying to get the highest MPG number possible at any cost so you can sound cool on a web site? So you get 1 MPG better. That's terrific, but what does that 1 MPG cost you? The oil is about 3 times as expensive. Do you make that up in the cost of gas? Is it really worth it??? To me, that's the question to be answered on gassavers.org. I'll offer whatever proof and hard data I can to help in those efforts.

Let me clarify a couple of things. I'm not trying to save money. If I wanted to save money all I have to do is turn the car insurance off and park the car and take the bus to school. Which is $23 a month. Compared to $100 for insurance and $100 for gas. $23>$200.

Next, I did a huge maintenance when I bought the car at the end of 04 and it would only get 28mpg on the freeway and at that time I was using mobil 1.

Now I get 40+mpg on the freeway. If you think it's a fluke then let me give you a math lesson. My car gets 20-22mpg on the street and when I fuel up my average is 30mpg. Now if 50% is city driving and 50% is hwy driving what's going to be the hwy number?
30mpg just doesn't come up like that or a couple dozen gas stations have their pumps broken. I'm kinda doing what Matt is doing, building a high mpg car at the fraction of the price. My goal is 35mpg mixed and that's it.

If I wanted to get the highest mpg at any cost I would syphon gas from around the neighborhood. Let me calculate 5 gallons of free gas and I drive for 150 miles. I don't know how to calculate it I guess whatever number of miles you get from stolen gas that's your mpg.

I'll be looking really cool when gas goes back up to $3 and I'm getting 50mpg on freeway. Not only will I look cool on this website but on the freeway too.

[jamescartagena]

Diamond Larry is correct. I am not an Amsoil dealer. I am just someone who tried a product and found that it worked for me. I do drive 25000 miles a year on my truck and every mpg makes a difference to my wallet. Also, it is much more convenient for me to change the oil once a year and knowing that it is protected for that time as I was changing it more often with Dino oil. I was thinking about becoming a dealer at one time but with a family and two small children, I don't have the time.

[n0rt0npr0]

All of my driving is 75% hwy.

Filter changes are dependant on analysis data, from 8K to 14K

My oil analysis is an easy single number. Values from 0-9
Test equipment? Northern Technologies International Corporation is the make.
LubriSensor Model NI-2B
This is what they call a portable oil analyzer.

I don't know what property of Syn oils would give me the 7% increase either, cosmicmc.

The analyzer works by comparing new oil, to the sample oil for each analysis. It compares the dielectric propertys of the oil samples. The difference is the number 0-9 (for synthetic, 8 is when you are suposed to change it, but I have gone to nine a few times.)

For more reading on the analyzer, go here to read about the "dielectric constant" (http://p2library.nfesc.navy.mil/P2_Opportunity_Handbook/6_II_3.html) and here is more about the analyzer (http://www.irbs.com/lists/trawlerworld/0004/0298.html)

I've given mobil one testimony by the way, they accepted it and never used it and made me agree that IF they ever do, to not expect any finacial benefits. shrug. Royal Purple is too expensive for me to consider giving them testimony.

And maybe there are just too many variables to go start making claims about fuel economy with mobil one. Maybe if they did, and ppl using thier products, away from the labs controlled test situations would start kicking and screaming "false claim, false claim" and woah, with the internet being ever so popular, them ppl could really put a dent in Mobil ones reputation. So they just don't put it out there, better safe than sorry?

[n0rt0npr0]

*

[CosmicMC]

I think the oil analyzer is useless for the purposes you use it for. It is designed for use with large diesel engines and diesel engine oils, not gasoline car engines. They are two completely different beasts. On top of that, the dielectric constant is only one of the four factors they use to determine the lifespan of the oil. The guy who's writing his story about using it is also using it with a diesel engine and Mobil Delvac diesel engine oil. Gas engines don't produce the soot that diesel engines do, and they also don't acidify the oil like a diesel does. The chemistry they used to design the analyzer is totally different from what your engines see, and for that reason I wouldn't trust that thing to tell me when to change my oil. A used oil analysis is the only reliable way to do it.

I don't think the synthetic oil is buying you any mileage increases at all. If you can document the exact conditions under which you came up with this number, we can all judge for ourselves. Lacking that information, I chalk it up to a psychological effect or invalid science. If synthetic oils bought you better gas mileage, their advertising departments would be all over it, especially with gas prices where they are. But strangely, they don't advertise that. Doesn't make any sense to me.

I'm not judging you, but I don't think your testimony holds water. I've been wrong before, so somebody rip my ideas apart and show me why I'm wrong.

[SVOboy]

Switching to synthetic lubricants - - engine oil, diff, Amsoil C+ Mopar-spec
transmission fluid, and syn greases in wheel bearings is good for 2-5% MPG
improvement. That is only about 0.5 mpg but every little bit helps.

Found this on a dodge ram forum.

<a href=http://www.dodgetalk.com/forums/showthread.php?s=6307d7191bb2c4c3bb9c69b5a0a7a6a9&t=28088&page=1&pp=20 target=_blank>Source</a>

[CosmicMC]

If you go on to read the rest of that article, as I just did, and you made all the modifications they recommend to save gas mileage, your mileage would go up by a minimum of 7.45 MPG, which would be about 40% better mileage than advertised on the window stickers. What do you think are the chances that Dodge would let a 40% mileage increase pass them by just because they didn't tell you to lower the tailgate, use different tires, index the spark plugs, use synthetic oil, etc. That whole article is a nice heaping, steaming pile of speculation, wild ideas, old husband's tales, and junk science. As if that wasn't enough, they said that lowering the tailgate would increase mileage, but removing it would decrease mileage, which is counter to the water testing that Mythbusters did. Those guys showed that you will get the best mileage with the tailgate UP because the aerodynamics created by the auto manufacturers take the closed tailgate into account in the design and deliberately create a "cushion" of air circulation behind the cab which deflects the airflow over the top of the tailgate so it doesn't create much wind resistance. If you lower the tailgate, the air flow comes down right on top of the tailgate and decreases mileage by increasing aerodynamic drag.

There are a few tiny nuggets of joy in that article, but for the most part it's a whole lot of hogwash, and even those few nuggets of joy cost so much to implement that it would take many, many miles to ever recover the cost of the changes. That's why Dodge didn't do it at the factory. If they wanted better mileage from their vehicles, they shouldn't have bought pickup trucks with 340 horsepower V-8 engines.

[Matt Timion]

If they wanted better mileage from their vehicles, they shouldn't have bought pickup trucks with 340 horsepower V-8 engines.

Can I give you a prize? :)

[n0rt0npr0]

Sorry I gave vague links and explanations to explain the device that I use to analyze my oil.
So I emailed NITC, and because of the type of industry they are (mostly govt contract work) they have a disclaimer on any email response given to me: Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by email.

But I am allowed to paraphrase from Molly Yoong--Lab Technical Service Coordinator--Northern Technologies International Corporation


The analyzer I use was discontinued in 2001. Very little info is left on this device. Back in 2001, sales stopped for other electronics (not the oil analyzers) products that were specifically used only in the steel industry. And you may know that the U.S. steel industry essentially collapsed in 2000-2001. Most customers at that time stopped buying (or stopped paying for what they had already received). Company went bust (loss of documents, equipment foreclosures blah blah)

And they reminded me that the analyzer is designed to analyze ALL motor oils. The reason is (which I appologize for not mentioning before) that every time you begin use of the analyzer, you zero it. You give it a "base" sample of perfect clean oil to compare the second used sample to. (link to a comparable analyzer (http://www.reliabilitydirect.com/oilanalysisproducts/SKF-TMEH1.htm))

Also, the govt link I gave where they list them four programs...It's an informational read only. It was wrote up to educate others on what programs are available for use by the military. They, the author of that write up, do not state in any way that they use ALL four.

Everything we test and modify on this board can be argued to "exact conditions"...I wouldn't try to take this past informational testimony. There are just too many variables. That is also the reason why the oil companies advertising departments aren't "all over it". It's just way too hard and expensive to prove, including my very own testimonies.

I'm curious as what credible documentation of these "exact conditions" would look like to you?

[CosmicMC]

The addendum to that email is a standard practice in most industries. It has nothing to do with government work or anything else. It's just a legal disclaimer to try and protect themselves against illegal use of proprietary information of any kind. That little paragraph means nothing about the credibility of the device, the organization, or the information they provided you. It's added automatically by a server in their email system.

So the first link you posted was for information and now you've posted another link to a comparable analyzer. The first one cost $700 and this one costs $1200. How long will it take to make up the cost of the device by decreasing the frequency of oil changes? On top of that, I think any oil company would say there's little chance this device gives you an accurate picture of oil life. It measures electrical properties of your oil, not lubrication or protective properties. Any information it gives you is based on the electrical properties of the oil, and there are so many factors about motor oil that affect its ability to lubricate and protect that this one piece of data can't possibly give you an accurate picture of the oil's actual performance. It's a ballpark guesstimate. I said it before and I'll say it again: A used oil analysis is the ONLY accurate way to gauge the health of your motor oil. This is true because a UOA does measure the actual physical and chemical properties of the motor oil and compares them against hundreds or thousands of known good and bad samples so a chemist can give you an accurate and informed opinion about the current state of the motor oil and how much longer it will last under the same conditions. No electrical device will ever be able to do that.

I applaud you for going to unusual measures to find economical ways to save on fuel costs, but I think you can do better than expensive electronic oil analyzers and expensive synthetic oils. It looks to me like any negligible actual savings are more than negated by these additional costs. I thought the point was to save money? If not, then what is the point?

Consider one more point about synthetic oils: What would they have to do in order to save fuel? They would have to reduce friction, right? Here's what Mobil says in answer to the question "What's the overall benefit of Mobil 1 with SuperSyn Technology?":

"The overall goal for Mobil 1 has always been to protect your engine, even under the most severe conditions, such as cold starting temperatures, extreme high-temperature operations and high-load conditions. Mobil 1 has been formulated with a performance reserve to provide you the peace of mind that your engine is protected during these severe conditions. But Mobil 1 with SuperSyn is not just for extreme service. You can also realize Mobil 1's benefits of improved engine cleanliness and extended engine life under "normal" service."

How many times in there did they mention reduction of friction or increased gas mileage? Zero. None. They never claim it because it doesn't happen. Reducing friction would be extremely easy to claim in a laboratory. How hard is it to claim extended engine life? That argument is ridiculous. They even TELL YOU that the oil will "provide you the peace of mind that your engine is protected," which is PROOF that they're banking on the psychological benefits. If you live in Fairbanks, Alaska and don't have an oil heater or if you live in Death Valley and you tow a heavy trailer uphill all day with the A/C running, Mobil 1 might help reduce wear levels in the engine. Is it ever going to pay for itself over this "extended engine lifetime" they're claiming? That's very unlikely.

What part of "the overall goal for Mobil 1 has always been to protect your engine" tells you that synthetic oil will save you any money, be it on oil changes, gas mileage, or engine lifetime? The benefits of Mobil 1 go to the yacht fund for Exxon/Mobil executives, not to you or your car. Do yourself, your car, and your wallet a favor and stick to conventional motor oil, get a used oil analysis done, and change the oil when the analysis says it should be changed and no sooner.

[MetroMPG]

cosmicmc, are you by any chance a lawyer? because you make a damn fine case.

the primary reason i switched to synthetic oil was for better cold-weather starts. on the handful of days each winter that are *extremely* cold, the difference between "go" and "no-go" can be marginal due to reduced battery output and increased internal drag from higher oil viscosity. under those conditions, i believe the more stable (i.e. higher) viscosity of synthetic oil (relative to the same weight conventional oil) helps tip the balance of probability to "go".

this is in line with the marketing from synthetic oil companies.

following that logic, it makes sense that while the engine is warming up to operating temperature (from a very cold start), it's running slightly more efficiently. however the difference is likely so small that if the oil companies publicized it (e.g. a comparison across a temperature scale), it would only serve to prove the null effect that synthetic engine oils have on mileage under "normal" (i.e. warm) operating conditions.

it is certainly so small that there is no cost-effective reason for using synthetics for the small mpg gain in winter use.

on the MPG issue, the oil companies stand to make more money by staying silent than they would if they revealed that there is actually just a small efficiency gain to be made under cold conditions for the brief period from cold start to normal operating temps. if they actually publicized that fact, they'd lose all those customers who are buying it because they assume because of its other documented properties, it *must* give better mpg.

by this logic, i should be using conventional engine oil in the summer. but i haven't been - i'm guilty of succumbing to the irrational hope that somehow synthetic helps me then too. but having read your comments and after thinking about it logically, i believe that will change next may.

it's similar psychological/irrational behaviour that led me to buy a K&N air filter for improved MPG... like Mobil, K&N also does not promise improved mileage anywhere in their marketing from use of their products.

last thought on synthetics: one area where they may make economic sense is in drivetrain components (transaxles/axles). since those components reach operating temperature much more slowly than engines, the advantage of low temperature fluidity of synthetic lubricants is more pronounced.

[SVOboy]

Me: Wanna tell me something about synthetic versus conventional?
DrDisco: i have a leather wallet
DrDisco: lol
DrDisco: synthetic huh
DrDisco: you can go 8000 miles between oil changes
DrDisco: and you can go 4000-5000 on conventional oil
DrDisco: don't believe the hype
Me: So there's not much of difference?
DrDisco: there is a large difference
DrDisco: i mean the hype of 3,750
Me: Oh oh oh.
DrDisco: you're dumping out good oil if you just drive around town
DrDisco: if you beat on it, 3000-4000 miles on regular
DrDisco: but generally twice as long on synthetic
Me: What about reduce friction with synthetic or those types of claims?
DrDisco: well that depends on the viscosity of the oil, since there's always an oil film on all the parts
DrDisco: that's the point of oil, besides cooling
DrDisco: but synthetic generally clings to parts better, so starts aren't as hard on the engine
Me: Does the better gas mileage with synthetic or certain types of oil idea hold any water?
DrDisco: lighter oil = less pumping losses and less friction
DrDisco: that's why the insight uses 0w-20
DrDisco: and why manufacturers are using lighter and lighter oils
Me: Yep.
Me: But will there be a mpg difference between 5w30 dino and 5w30 mobil 1?
Me: Or any difference besides lifetime?
DrDisco: i don't know, i'd have to see tests
DrDisco: dyno tests between oils can tell alot, or very little
DrDisco: depends on how they're conducted
DrDisco: replacing 3000 mile oil with new oil can pick up hp
Me: Have you seen the dyno testing of synthetic oil thread?
DrDisco: yes
DrDisco: but i think the question was whether the oil that was taken out was old, and of the same weight
Me: I'm talking about the tests to be done.
DrDisco: yeah, i saw that too
DrDisco: i'm waiting, haven't seen the latest
DrDisco: did the tests ever happen?
Me: Think the tests will be valid?
Me: Guy said 28th/29th prolly.
DrDisco: it sounds like he's trying to make them as good as possible
Me: The oils you mean?
DrDisco: the test
DrDisco: he's trying to control it pretty well, from what i remember
Me: Sounds good.
Me: You've been helpful.

DrDisco: well if an oil makes more power, it's because it reduces friction
Me: So wait for the dyno tests eh?
DrDisco: that helps not only power, but fuel economy, because you're spending less power fighting the oil, and using it to move the car
DrDisco: ya

So yeah, I'll wait on the honda-tech oil dyno testing and shall see.

EDIT: This guy is a honda technician and races on the side, as well as tuning and building engines, so I'd say he knows his ****, though he says he's been known to be wrong.

[Matt Timion]

I for one would like it if DrDisco would post this stuff on the forum himself. It seems like he has a lot to share.

[SVOboy]

Me: "I for one would like it if DrDisco would post this stuff on the forum himself. It seems like he has a lot to share."
Me: After I posted the oil stuff.
DrDisco: ha
Me: Why not, john?
DrDisco: i'll have to see, i have a lot of **** always going on
DrDisco: i guess i should show up there more huh
Me: You could.

[tvent]

Just wanted to share my synthetic oil experience. I'm not trying to set off the hole debate about synthetic vs. natural, again, just share my experience with the synthetic oil and a chevy dealership. It's been 3,000 miles since my last oil change and I asked for Mobile 1 synthetic 5w-30 (instead of what they put in by defult) for my 05' Chevy Aveo. So the bottom line is I got charged $71.44 for an oil change, $45.90 for the oil, 5 quarts. The Aveo owners manual says the car + filter holds 3.96quarts. After questioning why I was charged for 5quarts, I was told the spec.'s in my owner's manual are wrong? So, finally, I asked for the remainder of the oil I got the hell out of there. I'd change the oil myself if my living situation was more condusive, but man, it's expensive to get a synthetic oil change from a dealership!

[95metro]

Yeah, the synthetic isn't cheap. I don't know if the benefits outweigh the costs or not. I kind of offset the purchase cost of synthetic by running it longer than mineral oil.

Costs me roughly $15-$18 to purchase a gallon of standard oil and a filter. I used semi-synth for my last oil-change. $18 for the oil, $10 for the high-mileage Purolator filter. I'll probably change it in October.

[krousdb]

I paid $5.69/qt for my stash of Mobil 1 0W-20. It only takes 3 qts to fill between the dipstick marks. So it costs me $20 for oil and filter. I drop off the old oil at Jiffy Lube, no charge for that.

For me, DIY oil changes is a no brainer.

[philmcneal]

I'd change the oil myself if my living situation was more condusive, but man, it's expensive to get a synthetic oil change from a dealership!

exactly why i'm still on dino and i have 4 bottles of mobil 1 0-20w laying in my garage waiting to be installed...

[Silveredwings]

Synthetic just tastes better...and less filling.

[JanGeo]

Hey you guys should read the Synlube info about how all that petro based oil breaks down and the stuff Synlube sells is not petroleum based. Also you can only make a liquid so slippery no matter what you do to it, the rings still have to slide over a film of it. Now what Synlube does is use a solid lubricant that coats the metal parts in the pores making them smoother and seal against the rings better PLUS they lubricate at the top and bottom of the stroke when the rings against the walls are not moving for an instant which is when the oil film breaks down and causes a little bit of friction. The Synlube is still there making the walls of the cylinders slippery and reduces that little bit of extra friction. Also you don't have to change it because it does NOT break down into sludge like petroleum oils do plus because it seals the rings against the cylinders better you get more compression and less blowby keeping the lube (I don't call it oil) cleaner longer and the special filter (5-8 microns) cleans out the contaminents. Last longer, change less, or not at all 150,000 miles!

[psyshack]

Oil user here.

Ive used M1 with M1 oil filters or Pure One filters for years. Syn's handle low and high temps alot better than dino. They also have alot better add packs. I run my M1 10k miles easy. No more than 5k on dino's.

[MetroMPG]

They also have alot better add packs.

What's that mean, psy?

[psyshack]

Metro

All oils have additive packages. These add packs are the other half of the product. and what adds alot of the cost above whatever the base is whether its syn or dino.

Take the fact that syns flow better at low temps. thats because syn base stock just does this better. Then take the high temps that syn's handle better. Thats a result of the base and the add pack. Detergents and conditiners are part of the add packs. Along with stablizers.

It would seem that dino oils start breaking down before the additives. So they dont put as much in. Where as the additives start breaking down in syn base oils before the base does.

Take the Mobil Clean series of dino oils. I think there the 3000, 5000, and 7500. Basicly they just add more additives. Base stock is basicly the same.

Most name brand dino oils are good for 5k miles. Some can be pushed out to 7500 miles. But thats about the limit of dino oils.

Syn's like M1 and Amsoil can go 10k to 15k miles with no problems.

Oil companys make a big deal about there oils syn or dino but never speak much about there add packs. Thats where they all hide there secrets,, and there very hush hush about them.

[Ryland]

I have full synthetic oil in my car, and all of my motorcycles, and in my moped, everyone on MopedArmy that rides very much swears by synthetic two stroke oil for longer living engines, better power, I also have synthetic tranny fuild in my moped, and it runs so quite, and smooth.
I just put the amsoil 10w 40 in my honda CB125, and it's shifting better, and running better, I had maybe 400 miles on the dino-oil that was in there after an engine tear down to repair a pin hole in the crank case, the fact that it shifts smoother, and runs better I take as it lubricating better, last summer I did a switch from dino-oil to amsoil in my CB100, and I had a digital spedomitor, did a handful of test runs down the exact same road each direction clocking the speed at wide open throttle, repeated that test a few days latter, then changed my oil and did it again 15 minutes latter, and my top speed went up by 2.5mph or about 4%, and it has stayed at that top speed sence then.
my old 1984 civic DX hatchback I gained soild 3mpg, went from 39 to 42mpg when I switched to synthetic oil without doing anything else, no driving tricks, just straight highway driving at 70mph.
I've done so many other repairs on my civic VX that I don't know what my gains are, and I just recently got an amsoil filter, partly because they could sell me a longer filter (nearly twice as long) so I have more filter media, befor then I just walked thru looking at oil filters unill I found a 10 micron filter, and went with that, as that is the basic clame of the amsoil filter is that the filter down to ten micron, most that I looked at were 15-20 micron filters, if they stated it at all, and there is no standard that they are required to filter to, so unless they say how small, you don't really know what you are getting,
but the main reason I switched to synthetic is that I'm lazy, and don't like cralling on my back under cars to chage oil, and 25,000 mile oil changes sounded really good, and I've worked on enough engines that show wear, and scuff marks on bearings that a better oil had alot of appeal, I like things that I own to last as long as possible, so I maybe shouldn't, but I'll leave synthetic oil in my motorcycles for 2-3 years, insted of changing it every fall.
Matt started out staying however that his idle was lower, I found the opisit to be true, that the lower friction did rase my RPM enough that I re-adjusted it.
also amsoil is apparently made from Moble base stock, and that the aditives are the only real difference, the stablizers, and friction modifiers.

[katman]

AMSOIL is not made from Mobil base stock! Where in the world did you hear that?

[Ryland]

AMSOIL is not made from Mobil base stock! Where in the world did you hear that?

from two differnt amsoil dealers in wisconsin, close to where the amsoil compeny is based, is it not ok to buy your ingredents from the competition? and if that is the case then where are they getting them from?

[cheapybob]

I cannot prove Synthetics cause leaks. In 6 out of my last 6 vehicles I've visually encountered increased oil seepage AFTER I went from dino juice to synthetic. Didn't matter whether it was Royal Purple or Mobil One, after 500 miles of use, new spots of oil have occurred on my driveway. Mileage? I've made the switch as early as *edit* 20K to as late as 230K.
One advantage to synthetics I've found is a little better overall fuel mileage(went from 22mpg to 24mpg in one vehicle but generally 7% increase in economy)
I've done tests on dino oil, and I can't get dino oil to last longer than 8,000 miles in any 1988-1994 GM 60 degree V6 engine. My synthetics are lasting 25,000 miles by comparison. Using the same $6 filters too. Over three times the longevity there.
$13.50 for dino oil change
$32.00 for synthetic oil change

After 25,000 miles, I save $8 on the oil changes + the time involved to do them in my driveway + $431.22 worth of gas.
Well one more thing, I am not figuring the cost of "topping off" but as you can see with those gas savings, I wouldn't really need to.

So with 14 years of synthetic oil usage, I can conclude that synthetic oil use does lead to increased oil consumption but still significantly less overall than if you were to keep doing Dino oil changes every 8,000 miles.

We're here to contribute ways to make us less dependant on crude oil reserves, and this is just a small drop in the bucket but every drop counts.
~Will

No leaks here. I've seen studies somewhere that showed about a 5% increase in fuel economy from running synthetic vs dino oil. I run Mobil 1 and Purolator Pureone filters in all my cars unless I happen to find another good brand of synthetic at 1/2 off or something, which is rare anymore. I expect it will save some money, too, from the increased MPG's and extended drain interval. I haven't got the guts to run it 25k. The longest I've gone is 10k so far, with no ill effects.

[mtbiker278]

I've done a fair amount of reasearch on the differences between Synthetic and Conventional oils. I've even read some journal articles on tribology just to see what was new and up and coming, most of it referenced industrial lubricants though. Anyway, what I've come up with are these differences:

Conventional oil (Dino):
Base stocks are distilled crude oil that is refined several times, and separated based on their viscosity. Additives packages are added which include viscosity modifiers, friction modifiers, and anti-oxidizers. The additive packages are proprietary for each manufacturer, but on a whole are generally same with the exception of the amount and possibly the different friction modifiers. Molybdenum disulfide tends to be the favorite of the industry. Since the base stock is refined crude oil it has a whole bunch of "junk" in it. Plus, as stated from other members, it doesn't not have molecules of uniform size. These larger and smaller molecules tend to break down quicker than the "regular" sized hydrocarbons. This is the main reason why previous oil change intervals were 3k miles. Not to mention the refining process was not as efficient way back when. Now a days, you could go 5k miles on dino if you drive say 12k miles a year, and you're not racing the engine a whole lot.

Synthetic oil:
Based stock are made in a lab through chemical reactions. First developed by the Germans in WWII since their oil supply was cut off by the allies. Synthetic oil base stocks are 99% uniform. Synthetic oil base stocks can also have a different composition than dino oil. The more expensive motor oils tend to be PAOs (polyalphaolefins (http://en.wikipedia.org/w/index.php?title=Polyalphaolefin&action=edit)). Additive packages remain similar to conventional oils with a collection of anti-oxidizers, friction modifiers, and viscosity modifiers. Synthetic oils break down slower than conventional oils since the molecules are uniform size and composition. However, synthetic oils still break down, but their life span can range from 5k miles, to 20k.

It is my understanding that oil breaks down irreversibly due to heat. The way a hydrocarbon chain breaks down is by oxidization (essentially an oxygen molecule added separating the chain). The anti-oxidizers in the additive packages slow this process but can't stop it. In some respects an oil cooler could actually extend the life of your oil, but I wouldn't hold my breath on that since my guess would be the oil would tend to break down near the hot spots in the engine(cylinder wall, piston pins, etc).

As for FE, I have yet to see any test that conclusively shows a gain in between dino and synthetic. Most of the tests compare syn to syn, or dino to dino, or they just skip FE all together a look at wear and tear. The things that would increase FE would be friction modifiers, and viscosity modifiers. Obviously less friction and less pumping power needed would increase FE, but none of the modifiers currently used or tested show any substantial increase in FE.

So here is my take on this whole debate. If you drive little, don't thrash on the engine, and do a used oil analysis tests every so often, Dino oil is just fine. If you drive a lot, live on the redline, or even live in cold weather (dino doesn't make 5 weight oils as far as i know) then synthetic is probably a better choice.

As for me personally I use synthetic. I bought my car in Feb. and already put 9k miles on it. The DC area has a lot of stop and go traffic, high speeds, and stuff that generally does a number on an engine. I use synthetic just for the peace of mind. I plan on getting a oil analysis test done after my next oil change at 12k miles. I have never seen any increae in FE due to synthetic, although I don't have the equipment or the time to do any testing with proper conditions. If there was an increase, or even decrease, it was so small as to not be noticable through daily driving.

[katman]

There are a lot of over the road trucks with several hundred thousand miles on a single oil change. They use bypass oil filters that filter to less than a micron.
If you are reducing friction, FE has to go up! How can it not? If nothing else your vehicle will coast farther!
On my Tahoe, I changed the transfer case and both differentials to AMSOIL and got almost 100 miles per tank. The engine and transmission gave an additional 38 miles per tank. On my wife's 99 GMC 4x4 pickup changing the transfer case and both differentials to AMSOIL got 74 more miles per tank. She didn't get as much as me because she only has a 25 gallon tank and GM put a semi-synthetic in the rear differential. I still need to change her engine and transmission to AMSOIL. Till I install my bypass oil filter, i change my oil once a year and the filter twice.

[tvent]

After changing oil it seems like I notice that the cars I drive run smoother. I have no way to quantify how my car runs post-synthetic oil, but my car seems to glide/coast better down hill, could also be I put the tire psi to 36 well.

[krousdb]

36 PSI, livin on the edge!:D

[SVOboy]

Haha, you've never released the information on what you're running.

[krousdb]

Top secret! You will have to beat it out of me while you are helping me swap out my tranny, We will have vegitarian pizza I think.

[SVOboy]

As long as it doesn't have anything but cheese and sauce on it I'm fine.

[tvent]

36 PSI, livin on the edge!:D

There's somethin' wrong with the world today
The light bulb's gettin dim
There's meltdown in the sky

Ha! My tire says max is 44psi, Can anyone direct me to data on safety of inflating tires to max psi?

[SVOboy]

Dan's prolly running 70 or something like that. I am running 50, 44 max.

[Ryland]

I guess I rather trust the wear test that Amsoil, and I suspect other oil compenys refernce, and use to compair their oils to other oils, and I figure that if a more uniform oil provides better wear protection, and less brake down, alowing longer engine life, even without increased gas mileage, then it's worth it, the first time I used synthetic oil I wasn't really looking for better mileage, I thought that 38mpg out of a 20 year old car was good, but the car was in good shape and I wanted it to keep running for ever, replacing engines or cars as a whole adds up, so is there a draw back of useing synthetic oil? in my expearince yes, it will find leaks faster if they are already there, neither of my motorcycles, nor my civic leak a drop, my crx burns it maybe 1/3rd faster then dino oil, and with highway driving that is a quart and a half per tank (why it's waiting for me to swap to a lower mileage engine)

[philmcneal]

My tires say 51, running 62 front 60 rear.

[JanGeo]

Hey anyone have any luck finding this oil filter? Let me know - it's what I am using in my xB with the Synlube.

UPFL400A - AC Delco Ultra Guard Gold

[krousdb]

Dan's prolly running 70 or something like that. I am running 50, 44 max.

Ben, do you have a magic 8 ball also?:p

[diamondlarry]

Ben, do you have a magic 8 ball also?:p

I prefer tea leaves myself.:D

[tvent]

While I'm thinking about the oil in my car, what are people running for manual transmission fluid? I am assuming some form of synthetic. My car has around 7,500m on it, when should I think about changing it?

[krousdb]

I run 0W-20 Mobil 1 in both the engine and tranny. Smoooooth.But in no way is that an endorsement. You should decide for yourself.:D

[Ryland]

I started out useing synthetic 0w 30 in my transmition (hondas ask for motor oil, insted of gear oil) and with 220,000 miles a bearing started to growel a little, so after looking at the cost of a new transmition, I switched to synthetic 10w30 motorcycle oil and the growel disapeared, a few months after I put that oil in, Amsoil came out with a synthetic manual transmition fuild for transmitions that ask for motor oil, at some point I will switch to it, but for now I feel like I should get some use out of the oil I have in there.