Lowering your car in order to increase fuel economy

[Matt Timion]

Recently a few members of this forum have lowered their cars and have found an increase of fuel economy. krousdb noticed a 3 mpg impovement instantly.

Lowering your car will theoretically improve your gas mileage as it reduces frontal area of the car, lets less air under the car, and as a result increases the aerodynamic "flow" of your entire ride.

This thread will be a place to log results of this particular modification. Please give Fuel economy before and after. Please log as many tanks as possible for both the before and after condition.

[krousdb]

Recently a few members of this forum have lowered their cars and have found an increase of fuel economy. krousdb noticed a 3 mpg impovement instantly.

Yes but that is just one data point, new data that I was able to match with old data under very similar environmental conditions.

Since temperature has a significant impact on FE, and since my old data only contains results at temps between 18F and 30F on the AM trip and between 30F and 41F on the PM trip, as the days get warmer, I will have less likleyhood of finding matching old data for comparison. Hopefully, with a few more matches, I can be able to quantify the FE improvement with more certainty.

[Matt Timion]

Recently a few members of this forum have lowered their cars and have found an increase of fuel economy. krousdb noticed a 3 mpg impovement instantly.

Yes but that is just one data point, new data that I was able to match with old data under very similar environmental conditions.

Since temperature has a significant impact on FE, and since my old data only contains results at temps between 18F and 30F on the AM trip and between 30F and 41F on the PM trip, as the days get warmer, I will have less likleyhood of finding matching old data for comparison. Hopefully, with a few more matches, I can be able to quantify the FE improvement with more certainty.


now that you have the SuperMID, I do believe that individual trip MPGs will be sufficient for this type of experiment. If anything it will show that there is an increase in FE.

[krousdb]

Recently a few members of this forum have lowered their cars and have found an increase of fuel economy. krousdb noticed a 3 mpg impovement instantly.

Yes but that is just one data point, new data that I was able to match with old data under very similar environmental conditions.

Since temperature has a significant impact on FE, and since my old data only contains results at temps between 18F and 30F on the AM trip and between 30F and 41F on the PM trip, as the days get warmer, I will have less likleyhood of finding matching old data for comparison. Hopefully, with a few more matches, I can be able to quantify the FE improvement with more certainty.


now that you have the SuperMID, I do believe that individual trip MPGs will be sufficient for this type of experiment. If anything it will show that there is an increase in FE.

True, but will that be due to better aerodynamics or to higher temps?

[Matt Timion]

True, but will that be due to better aerodynamics or to higher temps?


I guess this is one reason to get adjustable coilovers, eh?

I guess as long as keep your temps consistent (as you compared this run to another run with similar temps) it shouldn't be much of a problem.

Maybe I'll install adjustable coilovers on my car this year in order to test this very thing. Lower it for highway trips.

[MetroMPG]

i don't have a hard time believing that krousdb's drop would net a 3mpg gain at highway speeds. don't forget it has also let him change his driving style slightly (less momentum lost in cornering), which also helps in lower speed driving where the aero effect is negligible.

one way i was thinking of testing this on a car with non-adjustable coils.... jack up each wheel from the suspension point (not the body/frame) so the spring compresses, and wrap nylon webbing or strong rope multiple times around the compressed coils. if the straps hold when you lower the jack, then you can do a relatively easy before & after run. just cut the strap for the "after" run.

makes it a little tough to do a proper a-b-a test though, since i imagine it will take 5-15 minutes to strap each spring (during which time the car cools down, weather/wind conditions change, etc, etc.).

and maybe it won't work at all (straps holding). i have no idea. but i was thinking of trying it.

i suppose you could try it with coil compressors too.

[MetroMPG]

Lower it for highway trips.

i think there was a lincoln that did this - one of the "mark xxx" 2-door coupes. yup, here it is:

http://www.dftowel.com/towelimages/MooseCarlisle.jpg

1997 Lincoln MarkVIII LSC
(from http://www.dftowel.com/lscsale/index.html)

And most interesting of all this car's great innovations and features is it's ability to lower itself at highway speeds. At about 50mph the car lowers itself to the ground for better aerodynamics, performance, and fuel mileage. The Mark VIII was featured in a TV commercial demonstrating it's ability to lower itself at highway speeds. You can see this ad by clicking here (http://www.dftowel.com/lscsale/TVad.html).

[SVOboy]

What the heck, that's insane! I wonder what kind of improvement their chalking that up to, though, ugly thing.

My camber kit shipped out today so as soon as I get that I will be dropping 3 inches or so, doing a camber kit diy, and an alignment diy, and we'll see how well that helps, :p

[krousdb]

Recently a few members of this forum have lowered their cars and have found an increase of fuel economy. krousdb noticed a 3 mpg impovement instantly.

Lowering your car will theoretically improve your gas mileage as it reduces frontal area of the car, lets less air under the car, and as a result increases the aerodynamic "flow" of your entire ride.

This thread will be a place to log results of this particular modification. Please give Fuel economy before and after. Please log as many tanks as possible for both the before and after condition.

Just a follow up on the return trip....

The trip back was 50.90, just short of my best return trip of 51.39. I did have a bit of a traffic jam that hurt. Without it I would have equalled the 51.39 at least. But certainly not 3 MPG higher like the morning trip. So far it looks like the lowering helps the morning trip, but not the evening trip. That doesn't make sense. More data points to come.

On a related note, the SuperMID says this tank is at 370 miles, 51.4 MPG. The digital fuel gauge shows 54.0 MPG. Perhaps I over compensated for the SuperMID over registration. Perhaps another tweak is in order after my next fill. I hope so anyway.

[krousdb]

- 3/7/06 Morning Commute: 21F, Dry roads, 10 MPH tail wind, engine on 72% of distance, 55.22 MPG

- Closest matching pre drop data:
2/27/60 Morning Commute, 18F, Dry roads, 10 MPH tail wind, engine on 72% of distance, 52.28 MPG

- Current Tank FE as measured by SuperMID
395 miles, 51.61 MPG

[philmcneal]

out of context i noticed you use mobil 0-20 for your transmission fluid. Is that the same as your engine oil, or different lubricant?

[krousdb]

out of context i noticed you use mobil 0-20 for your transmission fluid. Is that the same as your engine oil, or different lubricant?

It is the same for both engine and transmission.

[krousdb]

- 3/7/06 Evening Commute: 39F, Dry roads, 10 MPH head wind, engine on 78% of distance, 52.48 MPG

- Closest matching pre drop data:
3/1/06 Evening Commute, 41F, Dry roads, 10 MPH head wind, engine on 81% of distance, 51.39 MPG

- Current Tank FE as measured by SuperMID
421 miles, 51.66 MPG

[SVOboy]

Woot woot. That's pretty nice, m8. I got my front camber kit today so I'll be trying to drop 3" or so pretty soon, when I get my car running, :(. Junkyard tomorrow though.

[krousdb]

This trip started OK but I began to get concerned when I was dropping below my target FE at the various milestones on my route. I was downright pissed when my IGN off coasts were ending way too early. I almost pulled over to check if I had a low tire. But when I got to work I checked weather.com and found that my normal 9MPH tailwind had turned into a 6MPH headwind today. Not bad results considering a net 15MPH increase in wind speed.

- 3/8/06 Morning Commute: 26F, Dry roads, 6 MPH head wind, engine on 70% of distance, 54.29 MPG

- Closest matching pre drop data:
3/1/06 Morning Commute, 28F, Dry roads, 9 MPH tail wind, engine on 69% of distance, 55.00 MPG

- Current Tank FE as measured by SuperMID
447 miles, 51.80 MPG

[Matt Timion]

It's amazing to me how much you use wind to your advantage. Wind is never that consistent here, or if it is I never notice it.

[krousdb]

It's amazing to me how much you use wind to your advantage. Wind is never that consistent here, or if it is I never notice it.

During the winter here the prevailing winds are usually from the North. So most of my drive to work has a tailwind but its payback time on the evening commute. That is part of the reason why my FE differs on each leg. Other reasons are more traffic on the evening drive and +200 ft elevation difference.

Also be aware that when I say tailwind/headwind, that doesn't mean a perfect tailwind/headwind. It means that the wind usually at my back/front as my route changes direction several times. As the crow flies I drive SSW in the morning and NNW in the evening.

During the spring, summer and fall, the winds are more variable in direction and speed.

[MetroMPG]

It's amazing to me how much you use wind to your advantage. Wind is never that consistent here, or if it is I never notice it.

i suspect you may not notice it. it doesn't take much to have an impact.

also it's harder to "see" wind in the winter when the leaves are off the trees.

i did a drive a week or so ago and i was seeing 57-58 mpg at 80 km/h. i also couldn't see any wind. however when i headed back in the other direction it was obvious there was wind out there.

i tend to be very aware of wind anyway, since i sail a lot.

[krousdb]

It's amazing to me how much you use wind to your advantage. Wind is never that consistent here, or if it is I never notice it.

I have spent a considerable amount of time trying to adjust my route such that I have a tailwind on the way to work and on the way back. So far I have had only limited success. :-)

[krousdb]

- 3/8/06 Evening Commute: 41F, Dry roads, 9 MPH TAIL wind, engine on 80% of distance, 54.20 MPG, A NEW RECORD FOR THE EVENING COMMUTE thanks to the tail wind.

- Closest matching pre drop data:
3/1/06 Evening Commute, 41F, Dry roads, 9 MPH HEAD wind, engine on 81% of distance, 51.39 MPG

It appears that having a 9 mph tail wind versus a 9 moh headwind is worth nearly 3MPG.

- Current Tank FE as measured by SuperMID
473 miles, 51.93 MPG

- 54.5 MPG as measured by the digital fuel gauge.

[SVOboy]

Just fill up your damn tank and see if the MID or the fuel gauge is wrong!!!

On another note, I saw you say somewhere else that the del sol hasn't gotten the mileage you want. For serious?

[MetroMPG]

Just fill up your damn tank and see if the MID or the fuel gauge is wrong!!!

i see i'm not the only one interested in krousdb's daily reports :)

they make me want to go out and drive around - for no other reason than to see what kind of FE numbers i can get! it almost makes me wish i had to commute to work...

[krousdb]

Just fill up your damn tank and see if the MID or the fuel gauge is wrong!!!

On another note, I saw you say somewhere else that the del sol hasn't gotten the mileage you want. For serious?

What I said was that I was looking for a CRX HF or a Civic VX. The del sol is heavy and not built for FE like the others. i am very happy with what I am getting from the del slow but I coulda done much better with an HF or VX. Thats why I plan on the CX tranny swap and possibly the vtec-e swap. That way I get to have my sporty 2 seater with removeable top and awesome FE. For me, awesome FE is 70. But then again, I have been spoiled by the Prius. :-)

[SVOboy]

Ah, sorry, I was confused by what you had written. Another reason to get my car running is to pick up that tranny now that I'm on spring break.

[krousdb]

Just fill up your damn tank and see if the MID or the fuel gauge is wrong!!!

Patience young man, patience. The longer the test, the more accurate the results.

[krousdb]

Foiled by the headwind and wet roads. The warmer temps this morning appear to have been mostly negated by the wet roads when compared to yesterdays results. Tonight will be even warmer, 59F and I will have a 13MPH tailwind. Unfortunately there will be rain and that +200ft elevation change. :-(

- 3/9/06 Morning Commute: 44F, WET roads, 5 MPH head wind, engine on 67% of distance, 55.59 MPG

- Closest matching pre drop data:
No matching data. Temps too warm, winds reversed.

- Closest matching post drop data:
3/8/06 Morning Commute, 28F, Dry roads, 6 MPH head wind, engine on 70% of distance, 54.29 MPG

- Current Tank FE as measured by SuperMID
498 miles, 52.10 MPG

[krousdb]

WOOT!! Warm weather is here! At least for today. Even the rain held off and the tailwinds kicked up for my evening commute.:-)

- 3/9/06 Evening Commute: 64F, DRY roads, 13 MPH TAIL wind, engine on 80% of distance, 56.95 MPG. :-) :-)

- Closest matching pre drop data:
No matching data. Temps too warm, winds reversed.

- Closest matching post drop data:
3/8/06 Evening Commute, 41F, Dry roads, 9 MPH TAIL wind, engine on 80% of distance, 54.20 MPG

So it would appear that the 23F temp delta, and to a smaller degree a 4MPH heartier tailwind was worth 2.75 MPG or about 5%.

- Current Tank FE as measured by SuperMID
524 miles, 52.33 MPG, or 55.1 MPG as measured by the Digital Fuel Gauge.

It is beginning to look like I overdid it on the SuperMID calibration. If the digital fuel gauge is indeed correct, I will need to increase the SuperMID fuel parameter by 5.25% and likewise add 5.25% to my trip data FE. If so, today's evening FE would be 59.94 MPG. And the 3/6/06 morning commute of 58.36 would be bumped up to 61.43MPG. My current tank would then be 55.1 MPG, equivelant to the combined EPA estimate for the 2004-2006 Prius.


W000000t!!!

Ahem.... I think I should wait until I fill the tank before I celebrate. Hmmmm. Maybe tomorrow. :-)

[krousdb]

More headwinds and wet roads this morning, but warmer still.

- 3/10/06 Morning Commute: 53F, WET roads, 16 MPH head wind, engine on 69% of distance, 56.04 MPG

- Closest matching pre drop data:
No matching data. Temps too warm, winds reversed.

- Closest matching post drop data:
3/9/06 Morning Commute, 44F, WET roads, 5 MPH head wind, engine on 67% of distance, 55.59 MPG

- Current Tank FE as measured by SuperMID
549 miles, 52.48 MPG

[SVOboy]

Doing pretty good, d00d. It was that cold out in pittsburg today?

[krousdb]

Doing pretty good, d00d. It was that cold out in pittsburg today?

Yep, 53F, I noticed that it is warmer in your area.

I will fill tomorrow. At that point I will mafe the final calibration on the SuperMID.

[SVOboy]

W00t, I'm excited. Yeah, I was in shorts and a t shirt today and sweating, I hate the summer, grr.

On another note, all my stuff is in the mail to fix the car (I hope) so hopefully I can get that done and go run up and get that transmission and you can be like, 70 mpg, *smack*

[krousdb]

[quote=krousdb]OK, the last leg of the tank. I had a 12MPH cross wind, not sure it f hurt or helped.

- 3/10/06 Evening Commute: 53F, WET roads, 12 MPH CROSS wind, engine on 78% of distance, 54.16 MPG.

- Current Tank FE as measured by SuperMID
575 miles, 52.56 MPG, or 55.0 MPG as measured by the Digital Fuel Gauge.

I will fill tomorrow morning.

[krousdb]

The numbers below are corrected for the SuperMID error.

Pre Drop km/L km Temp MPG
2/28/2006 21.90 40.61 18 51.52
2/28/2006 21.24 42.33 41 49.95
3/01/2006 24.20 40.57 28 56.93
3/01/2006 22.61 42.10 41 53.19
3/02/2006 23.86 40.57 30 56.12
3/02/2006 21.50 42.34 41 50.58
3/03/2006 21.17 40.56 18 49.79
3/03/2006 20.73 45.90 39 48.75

Pre Drop ave temp 30.90F
% distance on wet roads 60%
Pre Drop ave FE 52.01MPG

Post Drop km/L km Temp MPG
3/06/2006 25.68 40.57 30 60.41
3/06/2006 22.40 42.24 40 52.68
3/07/2006 24.30 40.52 21 57.15
3/07/2006 23.09 42.26 39 54.32
3/08/2006 23.89 40.55 28 56.19
3/08/2006 23.85 42.26 41 56.10
3/09/2006 24.46 40.46 44 57.53
3/09/2006 25.06 42.20 64 58.94
3/10/2006 24.66 40.48 53 58.00
3/10/2006 23.83 42.21 53 56.06

Post drop ave temp 41.3F
% distance on wet roads 30%
Post Drop ave FE 56.74 MPG

I would say that given the variables of temp, wet roads, varying winds and lower ride height, one cannot extract the effect due to lower ride height alone. I would suspect that most of the gain came form warmer temps and dryer roads.

[Matt Timion]

I'll run this data later today and see if the temperature confounds the MPG or not. I'm guessing it actually won't. I say this based onthe fact that the temperature on many times goes down while the fuel economy goes up. Give me a few hours to get around to it.

[rh77]

W00t, I'm excited. Yeah, I was in shorts and a t shirt today and sweating, I hate the summer, grr.

You know what, I agree -- summer is not my favorite season wither. It was barely 70 today and I was sweating like crazy -- and I wasn't going to run the A/C in the car -- so around town it was fine with the windows down, but on the highway I subscribe to the theory that the drag induced is too much unless it's baking, then the A/C comes on. So to preserve good mileage, I had to use the vent blower, which was blowing out warm air for some reason. I had to crack the windows about a half-inch. Increased the Cd slightly (but not as much as the compressor, probably).

RH77

[SVOboy]

Not to mention that the summer in MO is friggin brutal. I'm out working on the farm in that crap too. One day I weighed myself in the morning, went to chop some trees out of the fenceline, came back at like 5pm, and I weighed 17 pounds less (and that included all the sweat still lodged in my clothing).

[rh77]

Not to mention that the summer in MO is friggin brutal. I'm out working on the farm in that crap too. One day I weighed myself in the morning, went to chop some trees out of the fenceline, came back at like 5pm, and I weighed 17 pounds less (and that included all the sweat still lodged in my clothing).

I bought my Civic DX without air when I lived in Ohio, and it got hot, but was manageable. When I moved to KC, it was so hot and humid in the summer, I'd be soaked by the time I got to work -- not really good for career advancement -- bought an OEM A/C kit and it bolted right in. That button was such a relief.

BTW, I saw the Civic Si at the auto show today. I just can't wait to drive one. The red Si guage lighting was classic, the LSD, underbody-pan for less Cd. The K-series would take some getting used-to, though. The Si Sedan will be identical, but 2 more doors, and expected to come out in April. 32 mpg hwy isn't bad.

RH77

[SVOboy]

PS to all: Look for a front camber kit DIY tonight or tomorrow for the ability to drop the car even further, :)

[Matt Timion]

The numbers below are corrected for the SuperMID error.

Pre Drop km/L km Temp MPG
2/28/2006 21.90 40.61 18 51.52
2/28/2006 21.24 42.33 41 49.95
3/01/2006 24.20 40.57 28 56.93
3/01/2006 22.61 42.10 41 53.19
3/02/2006 23.86 40.57 30 56.12
3/02/2006 21.50 42.34 41 50.58
3/03/2006 21.17 40.56 18 49.79
3/03/2006 20.73 45.90 39 48.75

Pre Drop ave temp 30.90F
% distance on wet roads 60%
Pre Drop ave FE 52.01MPG

Post Drop km/L km Temp MPG
3/06/2006 25.68 40.57 30 60.41
3/06/2006 22.40 42.24 40 52.68
3/07/2006 24.30 40.52 21 57.15
3/07/2006 23.09 42.26 39 54.32
3/08/2006 23.89 40.55 28 56.19
3/08/2006 23.85 42.26 41 56.10
3/09/2006 24.46 40.46 44 57.53
3/09/2006 25.06 42.20 64 58.94
3/10/2006 24.66 40.48 53 58.00
3/10/2006 23.83 42.21 53 56.06

Post drop ave temp 41.3F
% distance on wet roads 30%
Post Drop ave FE 56.74 MPG

I would say that given the variables of temp, wet roads, varying winds and lower ride height, one cannot extract the effect due to lower ride height alone. I would suspect that most of the gain came form warmer temps and dryer roads.


I tried to run this data today and came into a bit of a snag. Considering that two of the variables are continuous (temp and distance) and that one is categorical, I would need to be using multi-variate stats to determine if there was statistical significance or not. Since this is above my field of knowledge, I took the easy way out: I ran multiple tests.

Distance: Oddly, distance had a negative correlation with MPG. This really means nothing though as your distance was all very close.

Temperature: Temperature correlated to MPG (Pearson's Correlation) at .254. This means that the significance was .30. This essentially means that the temperature has no significant impact on MPG (in your case at least).

Dropping the car: This yielded the most interesting results. Comparing the MPG of the pre-drop and post-drop group yielded a significant result. It was significant to .002, which means that there is only a .2% chance that the drop did NOT affect fuel economy.

In other words, lowering the car works in krousdb's case.

[SVOboy]

In other words, lowering the car works in krousdb's case.

But how much is a matter of guesswork?

[Matt Timion]

In other words, lowering the car works in krousdb's case.

But how much is a matter of guesswork?

I'm unsure what you mean by this. Perhaps you didn't read this part above.

It was significant to .002, which means that there is only a .2% chance that the drop did NOT affect fuel economy.

[krousdb]

In other words, lowering the car works in krousdb's case.

See the Del Sol aerodynamics thread for highway mileage info.

[SVOboy]

I'm unsure what you mean by this. Perhaps you didn't read this part above.

I meant the amount by which is was affected.

[krousdb]

Temperature: Temperature correlated to MPG (Pearson's Correlation) at .254. This means that the significance was .30. This essentially means that the temperature has no significant impact on MPG (in your case at least).

Dropping the car: This yielded the most interesting results. Comparing the MPG of the pre-drop and post-drop group yielded a significant result. It was significant to .002, which means that there is only a .2% chance that the drop did NOT affect fuel economy.

In other words, lowering the car works in krousdb's case.


I am not going to argue with your results because I am not a statistician. But there are many reasons why FE should increase with temp. Faster warmup, (engine and drivetrain) and less dense air to displace as you move through it would be the major contributors. I am surprised that you found no correlation between FE and temp.

[Matt Timion]

Temperature: Temperature correlated to MPG (Pearson's Correlation) at .254. This means that the significance was .30. This essentially means that the temperature has no significant impact on MPG (in your case at least).

Dropping the car: This yielded the most interesting results. Comparing the MPG of the pre-drop and post-drop group yielded a significant result. It was significant to .002, which means that there is only a .2% chance that the drop did NOT affect fuel economy.

In other words, lowering the car works in krousdb's case.


I am not going to argue with your results because I am not a statistician. But there are many reasons why FE should increase with temp. Faster warmup, (engine and drivetrain) and less dense air to displace as you move through it would be the major contributors. I am surprised that you found no correlation between FE and temp.



Like I said, there was a correlation, just not a statistically significant one. I do believe that if you had a wider range of temperatures it would be a different story. Just looking at your data it's no surprise that no correlation was found. you often achieved higher FE with lower temps.

It can also be pointed out that once the engine is at normal operating temperature the effect of air temp is probably minimal. This has been demonstrated by non-hybrid drivers with HAI installed. Since most of these cars do not have a "lean burn" mode it is no surprise to find out that hot air has no real effect on FE after the engine is warmed up. See MetroMPG's experiment thread about the WAI for his results.

[rh77]

This has been demonstrated by non-hybrid drivers with HAI installed. Since most of these cars do not have a "lean burn" mode it is no surprise to find out that hot air has no real effect on FE after the engine is warmed up. See MetroMPG's experiment thread about the WAI for his results.

Balls! That stinks -- or might not be true in all applications. I need at least 3 independent tests to be convinced. I'd like to participate, since the weather is still cool, I could give it a try when I get back from Calgary on Monday (Vacation, woo hoo!). Depends on my schedule, but getting scientific numbers with this car is tough. I could give it a shot...

RH77

[Ryland]

If you lower your car, remember to get an alinement done as well, or your missalinement will cause even more drage.
I think it was a Nisson that is coming out, that lowers it's self at highway speeds as well, and because of how long it is, it's CD is almost exactly the same as the insight while at highway speeds, at lower speeds, when it has more clearance, it's two points higher, so if done right, like making sure that the front and back are both lowered the same amount, or lowering the front just a little more, and that you have wheels that are properly alined, then is should for sure help, less air under the car, is less drage, that is why the HF, and the VX hondas have the extra air dams, to reduce the air going under the car.

[SVOboy]

Dan has checked his alignment I am sure, we talked about it somewhere. When I smack my car to the ground I will do my own alignment and then have it checked by the computer when I have my 9 pound 13" vx alloys put on. That'll prolly wait until I can buy my new aftermarket shocks though and get them installed, don't want to go too low on stock shocks after all.

[krousdb]

Yes, I checked camber and toe in. The camber is out of spec (top tilted in, bottom tilted out)by a bit but the cornering is much improved. The toe-in is a little more than spec but my FE has nit suffered and the car still tracks straight. I have about 1200 miles on it since the drop and I do not see any unusual tire wear. I am monitoring it though.

[thisisntjared]

i might have missed this little tid bit earlier so forgive me if im wrong, but havent you guys considered that an increase in camber decreases rolling resistance as less of the tire is touching the pavement when driving without body roll. this is especially true when the tires are filled to the maximum psi.

also i think there are three real gains in aerodynamics for lowering the car. the decrease of frontal area for the tires is decrease. the upper half of the wheel(the part thats moving twice as fast into the wind) is tucked further into your wheelwell. by further i mean because of camber and because of ride height. and finally there is less 'free room' in your wheel well for turbulent air to flow around.

[n0rt0npr0]

I know this to be true! However, I have been trying for a month to find a shop that will specifically align the vehicle the way you want them to. On my vehicle I am allowed 4° +/- then the tires ride slightly on edge of course increasing rolling resistance. Wish me luck! So far the aim of the shop is "we will align it within that tolerance take it or leave it"

[rh77]

I know this to be true! However, I have been trying for a month to find a shop that will specifically align the vehicle the way you want them to. On my vehicle I am allowed 4° +/- then the tires ride slightly on edge of course increasing rolling resistance. Wish me luck! So far the aim of the shop is "we will align it within that tolerance take it or leave it"

Keep looking. I wanted an auto-cross spec alignment when I had my '99 Si. I got to know one of the mechanics at the Honda dealer, and he said he would do it. Basically rear toe was the biggie (camber wasn't adjustable, if I remember right) -- but it made it a little squirrelly on the highway - kinda twitchy in the rear but overall manageable. It really helped track the car better on the course. Downside -- big time tire wear. Probably the same if you change the camber. Also, Winter weather driving skills improved because they had to, if you know what I mean.

Maybe if you talk to a mechanic at a Chevy dealer he'll do it for you.

RH77

[SVOboy]

Downside -- big time tire wear. Probably the same if you change the camber.

Camber really has very little bearing on tire wear for most tires. As long as they aren't super low profile and have sidewall flex slight to moderate camber will not wear your tires out, it's all in the toe.

[n0rt0npr0]

Them dealers around here are exactly the ones who won't do it, but I haven't ventured past 15 miles yet into Detroits "little arabia". Them guys might just hook me up. I'll keep you posted.

Camber is adjustable. Caster is not. Caster is what a properly installed ball joint defines. It is "where" the tire is in relation to the a-arm(if ball joint is worn) and it also indicates how in-line the strut is with the ball joint. Camber is the inward/outward tilt (the one you adjust for auto-x) and toe is how parrallel pointed your tires are. IMO they need to be parallel unless you always drive off road. Driving on wet or icy/snowy roads with toe-in or toe-out is outright dangerous.

Drifters get large negative camber/caster(caster due to extreme lowering)
Conservative drivers for FE I would guestimate for negative camber also(or maybe just go to the outside of your normal specs like I want = 4° negative)
meh

[rh77]

Driving on wet or icy/snowy roads with toe-in or toe-out is outright dangerous.

How about rear tow-out on summer tires in snow? What? I was young and didn't know any better. BUT, I made it to work on a day they closed it due to adverse weather. It would've been nice to have gotten a call -- anyways, made it through the Winter ice/snow with no collisions. Granted, it wasn't a Michigan Winter, but it was a challenge. The next Winter -- all-wheel drive on Winter tires (check the avatar).

By the way, how do you get that cool little degree symbol?

Do you have a locally-owned tire shop that does alignments? They might be looser on doing a further range of adjustments. I'm guessing that near-Detroit GM dealers will probably be close to corporate on not bending the rules.

RH77

[n0rt0npr0]

hold down ALT then press 0176, release alt and °should pop up

I learned about it from character map inside windows (it shows all the equivalent keystrokes)

lol about your toe-out learning curve :p least you had all-wheel

Yes on many local owned tire/alignment shops...and they are the reason I pointed my nose toward dealers. Them guys are cheaper than the dealers but will not align it like I want. Then I called local dealers and like I said, I'll call some in "little arabia" and see what happens. I can get $15 barely used tires in little arabia (compared to $25 outside in the burbs) They just seem more willing to make the customer happy.

[DaX]

hold down ALT then press 0176, release alt and °should pop up

I learned about it from character map inside windows (it shows all the equivalent keystrokes)

°°°°°°°°°°°°.. ..*amused* :)

[mtbiker278]

So I'm looking into lowering my car. So far all I'm seeing is lowering srpings, but I have a feeling that coilovers are soon on the way. Anywho, not knowing much about suspension other than what's on mt.bikes I was wondering how my ride would be affected by dropped springs. Obviously the ride would be stiffer, but do I need to replace the shocks to a stiffer damper to compensate for the increased spring rate so the whole car doesn't bounch. Also, would coilovers be better in general because it'll reduce weight? Does anyone think that the suspension components from the SI would be interchangeable (A-arms, spindles, swaybar, etc.)

[SVOboy]

What kind of drop are you looking for? (I hate new cars)

[mtbiker278]

I'm not looking for much, maybe 1-1.5 inches (2" max). The roads around here are so messed up I wouldn't trust dropping it anymore than that. I saw a pothole the other day that would swallow my front end.

[SVOboy]

I that case I'd just get springs and not worry about replacing shocks also. I dunno if anyone makes them yet for your car, and they're prolly *** expensive.

:(

[mtbiker278]

so far I've seen Eibach, comptech, tein, and HKS that makes spring for the new civic. Some of them are only SI though. I wonder if they are interchangeable

[SVOboy]

Eh, I don't see why honda would give the si a totally different suspension. I can put 01 Integra Type R springs on my 91 CRX, :p

[mtbiker278]

good stuff. I suppose I could go and test drive an SI and stick my head under the car to figure out what's going on under there and compare it to my car.

[SVOboy]

Hell, just call the dealership, they'll tell you. Or check the part numbers online. How much are the springs? All those companies you mentioned are good stuff, so yeah. I'd go for about 1.5" Easy install, to boot.

[mtbiker278]

Eibach pro-kit $185.00 1" drop
Eibach sportline $209. 1.4" drop? (doesn't say)
Tein H-tech $189.00 1" drop
Tein S-tech $189.00 ($169.00 SI) 1.5" drop
H&R (some german company I've never heard of) $219.00 drop not listed

I thought I saw HKS, but was mistaken

My only concern would be if SI springs are shorter than the EX, but the ride heights are listed as the same on the specs for both cars.

[SVOboy]

I doubt they are shorter, but even so, if they are the same rate, once loaded it shouldn't make a difference, I don't think.

The sportlines might be my choice, I have skunk2, :p

[mtbiker278]

Cool, thanks for the feedback. I'll have to do some more shopping/investigating to figure out what I'll end up with. I also wonder if I can take the belly pan and rear tray from the hybrid.

[SVOboy]

The hybrid is only a 4 door, right? Which to me says no, you can do it yourself for cheap in any case.

[thisisntjared]

dont forget neuspeed. i love mine:)

[tomauto]

I have read that stiffer springs aid FE by reducing energy loss from the suspension working. It makes sense to me; just as mechanical brakes convert energy into heat, so do springs and shocks, so a stiffer suspension is not absorbing so much energy and converting it into heat, and ultimately that energy comes from the forward motion the engine supplies. Along those lines I tried a stiffer front sway bar and stiffer bushings- that proved to be a bit much. It "overpowered" the wheels and tires, by that I mean I could take corners at 80 mph with the tires squealing and that car wasn't leaning at all. It responded harshly to bumps too. Stock bar back in, but with the stiff bushings, restored much of the ride quality and the cornering capability hasn't suffered one bit.


There is no way that the suspension's energy loss can ever effect the cars mpg. First of all the suspension components move in a vertical or near vertical fashion. It could never aid in the vehicles' horizontal motion. Also, the suspension and the engine are totally different systems, and they don't another ones's assistance (i.e. taking or giving power) unless of course you are talking about the Bose suspension which was just spoken about in another thread recently.

[tomauto]

Although cutting your springs to make the car lower does help the overall aerodynamic efficiency (which is a step in the right direction) of your vehicle it isn't helping your ride or cornering ability, it is only bringing you closer to the ground and ruining the tuned factory settings which ford engineers worked hard on to give you the most comfort possible.

[MetroMPG]

I'd have to see a bit more info on the debate of energy savings from firming the suspension, but one of my first reactions is that while the suspension may be generating less heat, the vehicle still has to react to the contours of the road.

Where previously the unsprung mass of the (soft) suspension did most of the movement in response to road contours, a firm suspension transmits more of those contours to the sprung mass of the car body (thus the jiggly, harder ride). Since the body is much more massive, from an energy perspective what does that say?

EDIT: Hmm... then again, even the soft suspension "pushes" with the same force as the firm one, doesn't it? The difference being the inertia of the softer sprung mass (the car body) causes it to be steadier while the spring momentarily loads & unloads. I should just excuse myself from this debate now ... :)

--

On the topic of ride height & Cd, the 2006 Lexus LS430 with air suspension - which lowers the car about an inch at higher speeds - has a published Cd which is .01 less than the same car without the air suspension option. The comparison is quoted often (equating the Cd change solely to the active suspension).

[MetroMPG]

In the future I will refrain from posting such things unless the source is at my fingertips or I properly disclaim it as mere postulate

No worries. It's an interesting idea, even just to chew on.

[SVOboy]

hmm, i can't see ever cutting springs, especially not heating them. cut springs have a tendency to sag and heating changes the spring constant of the spring, not my cup of tea. also, i wouldn't lower 2" on stock struts, they're just not made for it, not enough damping ability, do you bottom out at all?

hopefully you have nice roads and won't lose your struts to them, :p, i'm only lowered 1.5" on tokico illuminas and i fear every bump might blow my shocks out, but i'm paranoid.

anyway, the spring rate argument is something i've read a lot but have no idea about. hopefully you guys will turn up something good in search.

[SVOboy]

I have just seen too many pictures of springs that've sagged from being cut, or shocks that've blown out from being lowered on. So that's where my bias comes from. I rode my car 2" lower on 20$ lowering springs and it rode like crap, so I went and spent some money on shocks that were tougher to stiffen up the suspensionso I wouldn't bounce around like I had pogosticks in there.

Anyway, these are just my experiences is all.

[kickflipjr]

I have also thought about the loss of engery in the suspension and engine mounts. If bother were firmer would there be a change in overal mpg? (probally not). The energy is probally tansfered to the body of the car.

About motor mounts. Dosen't make sense if you put race(solid) mounts in a car it would improve mpg because less energy is wasted in the engine going back and forth? or is that energy just sent to the rest of the car body and shows no advantege at all?


I noticed road bikes (bicycle) never have shocks and are intentially made to be stiff. This is because energy is lost in the shocks. But bicycles and cars are very different, but the efficiency is simillar. Thin tires/ High PSI/ Aerodynamic shape/

[SVOboy]

I'm not looking at the car, I'm looking at the posts people make like "oh snap, I cut my springs and it was fine for a few months now one side is sagging" or "I lowered my car and blew my struts out, what should I do?"


Shocks blow from bottoming out internally because there is less shock travel on a lowered car. Plus the stiffer springs make greater change or something like that which puts more stress on them, I'm not sure on that second pard.

What you need to keep in mind is that I have no idea how ford stuff works, this is all honda knowledge. I have driven a nissan once that broke a coil off a spring and that shock was extremely trashed, but that could be the unevenness.

[SVOboy]

I think hondas might have less suspension travel. We also have some of the best stock struts I've know that are made, on our nice suspension that we have (screw you, mcpherson).

I'm not sure about how people cut, just know that when I first heard about it years ago it was my cousin complaining about how his friend cut and screwed something up, Iono, it was so long ago, and the was a DSM.

[Ryland]

I've been asking around at the auto parts stores about lowering, and they said that if you want to lower a Honda 1" that you can get lowering springs, and have to use stock struts, to go lower then that it sounds like you can use stock springs, and get adjustable struts to lower, it looks like the adjustable limitations are around 1.3" to 2.5".
the rear of my car has new stock hight springs and struts, and sits a little over 1" lower then the front because of how I use my car (hauling tools, food, cloths, camping gear), so I really want to lower the front to match the rear, but I need to figure out where to measure hight, is it the jack point? the floor pan? the fender lip? the bumper lip?
I can only imagine how much drag it causes haveing the nose of my car sitting over an inch higher.

--Ryland

[SVOboy]

Iono what the auto parts stores are telling you, but it sounds like they're full of it. I wouldn't mind a 1" drop on stock struts if you got some decent springs, but crappy springs will kill at any level of drop.

They do have adjustable shocks that lower, but what they prolly mean are adjustable stiffness, like my tokico illuminas or kyb agxs. Koni Yellows are adjustable both by height and stiffness, but there's not point putting a stock spring on a yellow and adjusting down the half insch it allows you. I generally measure from tire to wheel well to make sure things are even.

[ZugyNA]

I've been asking around at the auto parts stores about lowering, and they said that if you want to lower a Honda 1" that you can get lowering springs, --Ryland

Or...you can install a pair of these on each spring for less than $40. They aren't that easy to get in there...but they both lower each spring by one coil and stiffen it even more by acting as stops for the coils above and below.

Need to watch for interference with sheet metal and so forth...and snug them down good so they stay on opposite sides of the spring.

I had these on a sports car with crapped out struts and it still handled real well.

http://www.nonags.org/members/nijqk/saddletypeboosters.jpg

[SVOboy]

"these" I wonder if you're talking about those little stop things. Saw them once on a 49 ford hemi...

[MetroMPG]

Or...you can install a pair of these on each spring for less than $40 http://www.nonags.org/members/nijqk/saddletypeboosters.jpg

A pair of what? (Maybe you posted a link that didn't come through?)

[Ryland]

the reason you don't want a bicycle with soft shocks is that when you are "standing" on the bike to pedle harder, like going up a hill, the shocks are compressing every time you pedle and are absorbing the energy you are trying to put to work, this is why quality suspention parts for bicycles come with a lock out, to "turn off" the shock and make it extreamly stiff.
with cars, you do want, to a point, soft suspention so that the tires will role over bumps and dips smoother without making the whole car move up or down that fraction of an inch, hitting a bump is like going up a tiny hill, and if your whole car has to go up that half inch, or whatever it's going to take more energy, from what I've read, stock honda's come with suspention that is tuned for traction, not for comfert, their struts are designed to let the wheels recoil back to the pavment faster then they lift, thus the ride feels "rough" because you feel more of the tiny bumps.

[ZugyNA]

A pair of what? (Maybe you posted a link that didn't come through?)

Might have to right click to see the pic? It's there.

[MetroMPG]

Got it now - thanks. Interesting.

I've been experimenting with a 1-inch drop recently. You'll all laugh when you see how I did it. I'll see if I can get a pic in the next day or so.

EDIT: should have said I've been "playing" with a drop - no experimenting involved :)

[zpiloto]

Might have to right click to see the pic? It's there.

I'm still not seeing it:confused:. Where is the link?

[MetroMPG]

http://www.nonags.org/members/nijqk/saddletypeboosters.jpg

[SVOboy]

That's not helping either darin...

[MetroMPG]

Didn't a clickable link appear in my message? (#96)

[SVOboy]

With this text:

http://www.nonags.org/members/nijqk/saddletypeboosters.jpg

[Matt Timion]

To view the image:

To to www.nonags.org

then go to the URL. It must be in the same window/tab.

[SVOboy]

Aha.

[MetroMPG]

Strange. Worked first time for me, no special steps. Just click = pic.

[Silveredwings]

Do they ever get loose if you bottom-out?

[ZugyNA]

No. You snug them down tight...they don't move. They have high grade bolts.

You do need to be sure they don't hit sheet metal and you might need to shorten the bolts...main thing is to not nick, cut, or scratch the coils. The end pieces are softer steel.