New Car Comparisons

[northboundtrain]

Sitting home with a sick kid today, and I'm entertaining notions/fantasies of replacing the old dirty diesel with new car. Using official EPA estimates and MSRP, I've compared sticker price to fuel savings for the prius, corolla, and yaris. Figuring gas at $3.00/gal in today's dollars, I found that the pruis and yaris would each have to be driven 312,800 miles for the fuel savings of the prius to equal the difference in sticker price. This assumes equal maintanence costs, which is unlikely, especially given the prius would probably need two battery replacements over this many miles. For the corolla-prius comparison, the break-even point is 207,340 miles, again assuming equal maintanence costs.

A VW tdi (when they start U.S. Production again) would have an even higher break-even number of miles compared to an entry-level economy car given it's likely higher sticker price (not to mention maintanence costs).

Not that saving money is the only consideration, but likewise, mpg isn't the only consideration either when considering overall environmental impact (the batteries of a prius are extremely environmentally destructive to manufacture).

Anyway, this is just food for thought when trying to make sensible purchase decisions. . .

[SVOboy]

I would go with the prius. I think it can be pushed a little bit harder on the FE and the emissions and such are lower. I would also wager it would have a much higher used price, so if you figure your calculations 8 years away with 120k on them, I think you'd make a few thousand back on the prius.

[MorningGaser]

ConsumerReports does not often like VW, so I would stay clear of them, especially those made in Mexico.

Being a Yaris owner, I can say that it is a great car, and I get better then Prius in the highway (46mpg), but not city (36.3). I think that if you factor in the cost of ownership, including depreciation, fuel, and maintenence, you would save money if you went the Yaris route, over the Prius. Of course the Prius is bigger and more comfortable, but these issues aside, the Yaris is better for saving $$ on gas, and they sell very nicely equipt new for $13,000 too.

[rh77]

It depends on the size you need and the cost. The Corolla is a good choice -- fairly low running costs and good FE. The Prius is also an excellent choice. I agree with VW vs. Consumer Reports. The stats speak for themselves.

I almost always recommend Honda, but lately, they've seemed high-priced and rather thirsty. I saw a truckload of fresh '08 Accords come out of the Marysville, Ohio factory last Friday -- they looked like a BMW 3-series!

I haven't had the chance to post the data, but I've rented several automatic Corollas this past year, and averaged around 32 mpg at 65 mph for a cumulative distance of 2500 miles+. A manual and better technique could get you up in the 40's and 50's. The Prius is capable of much more, but with more up-front cost and learning new technique. I'd stay away from the Matrix/Vibe due to FE issues.

I also really like the Kia/Hyundai offerings -- specifically the Spectra/Elantra (granted they generally have an iron block, but mileage is on-par to Toyota, with more safety features and a better warranty).

If a small hatch is on the radar, look at the Yaris. Drive 'em and see what you like

If emissions are a top concern, I've often looked at a Civic GX Natural Gas sedan. If you live in an "approved area" with home natural gas, you can fill-up overnight and have about a 250-mile range. High upfront costs with the "Phill" unit and vehicle are there, but longevity is a big plus. Downside: auto only.

RH77

[MorningGaser]

Originally Posted by rh77

I also really like the Kia/Hyundai offerings -- specifically the Spectra/Elantra (granted they generally have an iron block, but mileage is on-par to Toyota, with more safety features and a better warranty).

The Korean jobs are in fact NOT on par with Toyota in regard to milage. They are 10% or more behind in fact.

And although the Korean jobs cost less, the Yaris has a lower cost of ownership then the corresponding Korean models.

Also, there is a reason why the Korean models need the 10 year warranty...think about it, and if you do, you'll see why the Toyota 3yr/36k warrantied cars are better.

[northboundtrain]

Some questions:

Suppose I got a corolla. What are some mods would you all recommend that would return gains in FE and keep the car under warranty. The idea of a nice clean burning reasonably priced car with adequate power (read: get up mountain passes w/o hazard lights flashing) that could realistically get mid 40s mpg or higher is starting to sound rather appealing. Even though I can burn biodiesel and get mid 40s mpg in my Jetta, I'm starting to feel a little guilty when I see the black film of particulate covering the back of my car (bad emissions and bad aerodynamics). Not to mention, 52 hp just plain sucks sometimes.

Also, how is the corolla geared for highway cruising as opposed to the yaris, or fit or civic for that matter?

[omgwtfbyobbq]

Originally Posted by northboundtrain

Even though I can burn biodiesel and get mid 40s mpg in my Jetta, I'm starting to feel a little guilty when I see the black film of particulate covering the back of my car (bad emissions and bad aerodynamics). Not to mention, 52 hp just plain sucks sometimes.

Back your *smoke screw down until it goes away and put on a underbody tray/toss a properly designed spoiler on the end of your trunk. If you want more power w/ modern emissions, drop a TDI in. It'll definitely be less money and more usable power provided you can wrench on it yourself. That being said, a Corolla or Yaris would do pretty well and are already optimized for aero to an extent. The only thing I can think of would be a better spoiler, but newer cars have the air flow around the sides instead of dealing with a strict 15 degree angle from the top of the car to the trunk, so I wonder if that'll even work.

*Black smoke equals money wasted out your tail pipe, not to mention you'll actually make less power compared to a mixture that isn't overly rich.

[northboundtrain]

Originally Posted by omgwtfbyobbq

Back your *smoke screw down until it goes away and put on a underbody tray/toss a properly designed spoiler on the end of your trunk. If you want more power w/ modern emissions, drop a TDI in.

The smoke screw adjustment is a balance between adequate power and foul exhaust. I've backed it way down for emissions testing and walked away with riduculously low particulate percentages, but the car could hardly get out of the parking lot with that "tune." I have thought of a spoiler, underpan, and many other mods, but that will only happen if I actually decide the car is worth the significant investment of time. As for "dropping" in a TDI, I'd rather drop the car off the nearest cliff and sell it for scrap metal than waste that kind of time, energy, and money in a such a POS

[omgwtfbyobbq]

With that little power you likely backed it down too much for the test. There's a point where you'll get a little bit of smoke if you bog it too much, but you'll have all the power you should have stock. Any more, and it just gets dumped out the back in the form of smoke since you have no way of increasing air flow proportionally. These engines were designed to rev, so you can bump up the fuel screw for more torque down low, but it'll change all kinds of things, and IME, generally hurt top end power. As for the TDI swap, in terms of time and energy, it's not a hard swap AFAIK, but if you don't wanna you don't wanna. I bet aeromods on bricks like these would make themselves up in less time spent at the gas station provided you keep the car for more than a year, but from what it sounds like, you don't exactly plan on doing that. :P

[northboundtrain]

I have thought of completely overhauling the jetta with radical aero mods, a taller geared tranny from a gasser, rebuilt engine, weight reduction, etc. I could probably get 60+ mpg. But the amount of work involved is staggering, and still it would have 30 year old engine technology that will never have better emissions than you could get out of a tractor, not matter what you do to the fuel screw, and you're still way underpowered.

There was a time when I was really psyched to dive into such a project, but now I question the point of it. Why bother? To prove to myself it could be done? Because it would be more fun than any other way I can think to spend my time? In the end, I still have a dirty diesel in a cheap car and the months of work that went into it are valuable only to me.

I'm definitely the type to prefer the DYI hard way over the just-spend-the-money-and-be-done-with-it easy way, and if I could be convinced of the value of such a project, I'd launch into it tomorrow, but right now it doesn't seem worth it. I've already spent a lot of time working on this car and my previous rabbit when I could have been playing with my kids or getting worthwhile house projects completed. So yeah, it might be time to rinse my hands of this thing. . .

But this thread is starting to wander from the original intent.

[omgwtfbyobbq]

Um.... Well, I can't argue with someone who already knows they know what they know and that's that, however, a couple of points even if they are OT. In 1977 VW's diesel emissions were pretty much what 2004 OTR rigs have to meet. I know of no *current emissions regulations of off road equipment like tractors, so... I really don't think a car built in '91, even a diesel, will have emissions that are as bad as any tractors, at least at the factory settings, less the owners who screw with the smoke screw of course. If you really think the two mods that would improve mileage the most, a transmission swap and a few pieces of corrugated plastic are going to take you months, then I agree completely that it's not worth it. No mechanicing for you...

That being said, I expect all the time I've put into my diesel (~30-40 hours) would repay itself if I sold it given the likely current market prices compared to how much I have in it, imo at least. Compared to other vehicles, tuning, power upgrades, and replacement parts are fairly cheap and totally legal unlike any modifications of gasoline vehicles in these parts. There is a huge knowledge base out there, and these cars are fairly decent overall if kept up with 60mpg combined attainable no sweat in the experience of myself and others.

I bought a '91 diesel Jetta 2 years ago. We did a few basic repairs and have put on a pile of miles. It has started at 40 below (plugged in) and has been quite reliable. Have found that VW parts are often chewaper and much better thatn 'jobbers' - especially the transmission seals. My son drove the car at 90 kph (50 mph) for eight hours the other day and got 60 mpg!

*CARB is going after commercial.off road, and marine diesels right now, but standards aren't in place IIRC.

[northboundtrain]

I'm going to try to restore this thread to it's original intent. omqwtfbyobbq, your ridicule aside, I appreciate your points and if you'd like to continue discussing the merits of restoring and modding my jetta feel free to pm me, or perhaps we can start an new discussion in the diesel section.

I found some good info on civic, fit, yaris, and corolla tranny/axle ratios over on cars.com. For '07 models with stock size tires running at 70 mph (which is a realistic highway speed for me) the civic is doing 2,948 rpm; the fit is at 3,337 rpm; the yaris is at 2,962 rpm; and the corolla with stock axle gears is at 2,763. But, according to cars.com -- and I'd need to varify this -- the corolla can be had with an optional 2.96 ring and pinion which creates much taller gearing and has the engine spinning at only 2,076 rpm at 70 mph! This, it seems to me, puts the corolla in league of it's own for FE potential.

Any thoughts or ideas about this? Any corolla owners with the taller gears?

[SVOboy]

I've never heard of that option on the corolla! Interesting. I would say it's a good option if you don't want to go for the prius. What're the emissions scores of the corolla v. vitz?

[omgwtfbyobbq]

The A245E has a .892 fourth and 2.96 R&P according to wikipedia with the engine speed at 70mph being about 2500rpm, which seems consistent with the gearing on my grandfather's Corolla. He gets anywhere from ~40mpg@60mph to ~25mpg in town, drives like most but is a bit on the slow side. I apologize if it seems like I'm ridiculing you, but I tend to tease those who haven't invested a little bit of time/research into their cars, imo of course. Your best bet for fuel economy isn't going to be a new car based on what manufacturers are offering. You'll likely either have to pay a premium for a car that can get fairly good mileage like a Prius, or spend less for a car that doesn't do quite as well. If you want good mileage at high speeds in stock form, your best bet imo is an early nineties Honda. Anything built in the 90s w/ a CX/VX transmission, or a 92-95 CX/VX would be the best bets imo. I think some Saturns also came from the factory with fairly favorable gearing, but I'm not sure which ones they are.

[northboundtrain]

Originally Posted by omgwtfbyobbq

Your best bet for fuel economy isn't going to be a new car based on what manufacturers are offering. You'll likely either have to pay a premium for a car that can get fairly good mileage like a Prius, or spend less for a car that doesn't do quite as well. If you want good mileage at high speeds in stock form, your best bet imo is an early nineties Honda. Anything built in the 90s w/ a CX/VX transmission, or a 92-95 CX/VX would be the best bets imo. I think some Saturns also came from the factory with fairly favorable gearing, but I'm not sure which ones they are.

Well, I'm looking for the best mileage I can get in a four door car that's relatively safe (have two little kids). I know there were four door metros, but the CRX and VX are both two door cars (I think the VX is at least). I also want something that can pull it's weight in the mountains. mpg_maniac is getting 53 mpg in an '06 corolla which seems pretty good. But if there's good options in the older used offerings, I'm all ears -- would rather not have to pay for a new car and insurance, registration if I don't have to.

[northboundtrain]

Here's the page on cars.com indicating the available 2.96 ring and pinion ratio. http://www.cars.com/go/compare/trimC...=USB80TOC041A0 The axle ratio is given near the bottom under Mechanical. I have not yet found further confirmation, but I will continue to look into it.

The car comes stock with 24.5" diameter tires (185/65/15). So the math indicates 1,927 rpm at 65 mph, 2,076 rpm at 70 mph, 2,224 rpm at 75 mph, and 2,372 rpm at 80 mph. These are very low rpms compared to the typical car these days. With a respectable drag coefficient of 0.30, I would think the corolla might be one of the best FE potential new cars in the non-hybrid, non-diesel catagory.

Edit: The page on cars.com lists the fuel economy as 18/27, but the updated EPA numbers are 28/37 with the 5 speed.

[omgwtfbyobbq]

You should call Toyota to be sure, but I think only the auto has the tall R&P. Go here and check out the axle ratio for the five speed. It seems to be 3.94 with a .73 OD. Here's another mention of the taller R&P, but it's for the auto. Maybe try calling a Toyota dealer and see if you can source a taller manual for it? I think it could easily get ~50mpg@50mph average speed, but not at 70mph. If you don't want to mess around with dropping a CX/VX transmission into a four door, and have the NG refueling stations around, a Civic GX may be the best bet. With the phil it's supposedly as cheap as $1-1.50/gallon equivalent. Or an HX coupe, but the overall cost would be higher for the HX.

[theCase]

Originally Posted by northboundtrain

With a respectable drag coefficient of 0.30, I would think the corolla might be one of the best FE potential new cars in the non-hybrid, non-diesel catagory.

I agree with this assessment. I've got an '06 Corolla, auto tranny and have averaged over 42 mpg on 9000 miles since I started tracking it in May.

Only mods are 42 psi tires, grill block (inside the grill) and a hunk of cardboard over the top of the engine to keep it warm. Driving is about 85% highway with a 80 mile daily round-trip commute.

Thinking of trying WAI, but I just don't think it would help. Next week I get my ScanGauge, so watch out!

[northboundtrain]

Originally Posted by omgwtfbyobbq

You should call Toyota to be sure, but I think only the auto has the tall R&P.

I think you're right. The taller gearing with the manual tranny would be pretty extreme (too good to be true?). Even still, the corolla 5 speed has pretty tall gearing compared to others. It does 2,763 rpm at 70 mph, which is about 200 rpm better than the civic or yaris and almost 500 rpm better than the fit. Now if only it could be had with a hatchback and keep the 0.30 drag coefficent

[omgwtfbyobbq]

What about a new or used four door or hatch Yaris? Cheap for a newish car, likely reliable, has airbags and all that, a Cd=~.3 for both from what I've searched, and with a C54 manual trans, the axle ratio is 3.94 w/ a .86 fifth. The ratio of displacements to fifths is about the same at .2 over so engine efficiency should be similar especially since cars d0t com has the 5th at .82. A new 4 door comes in at ~$12,500 w/ AC/MT, but w/o CC/PW/PD/etc...

[Telco]

No way I'd be considering any new car, unless I was buying a Lexus SC-430. That's the only car on the road today that IMO is worth paying new for, and that's just because I have a thing for hard top 2 seat convertibles. Yes, I know it's really a 2+2, but at 6ft 4in, nobody's going to fit behind me so if I bought one, I'd drive it straight to the upholstery shop to have the rear seats removed and the rear seat area carpeted and soundproofed so it looked and sounded like a factory 2 seater.

I'd suggest looking at an off-lease model, they tend to be thousands cheaper, usually have less than 30K miles, and are usually well-maintained since the maintenance has to be kept up as part of the lease deal to avoid penalties. Might be able to get an 05 for about 50-60 percent of the cost of a new car, and if you think about it, once you drive that new car off the lot, it's just as used as the off-lease model.

[northboundtrain]

Originally Posted by omgwtfbyobbq

The ratio of displacements to fifths is about the same at .2 over so engine efficiency should be similar . . .

Hmm, good point. Comparing rpms is not an apples to apples comparison given different engine specs. However, tire size should still be considered. Also, I think piston speed is the critical factor in engine efficiency, so stroke length is the more important number rather than displacement (though the two are generally related). So let's compare the corolla and yaris again:

At 70 mph, the corolla's engine rpm is 2,763, while the yaris's is 2,962. Since tire diameter was used to derive this number, we've accounted for the tires. Now multiply the rpm by the stroke length, and we have a relative measure of piston speed. Since the corolla's stroke is 3.60" and the yaris's stroke is 3.33", these numbers are 9,946.8 and 9,863.5 respectively. So the yaris pistons are actually moving a tad slower at a given vehicle speed, making it, in theory at least, the more efficient of the two. Combine this information with the yaris's lighter curb weight, slightly better drag coefficient (0.29 for the sedan), smaller diameter and narrower tires, and I suppose the nod has to got to the yaris. But, of course, the corolla has a better crash rating and is a little roomier, though it's $2,000 more expensive. . .

By the way the rpm x stroke length numbers for the civic and fit are 10,141 and 11,746 respectively.

[jwxr7]

I went thru this too, but for my wife who needed an automatic. We ended up with a '08 civic 5spd auto. If you can live with an automatic (I can't), these seem FE minded.

I was curious, so doing some calculations to compare to the piston speed #s above... The engine has a 3.4" stroke a, I believe a 4.29 final drive, a .53 5th gear and 205-55-16 tires (about 811 rpm @ 60 mph according to http://www.miata.net/garage/tirecalc.html). So I calculate the engine to run 1844 rpm @ 60 mph and 2151.3 rpm @ 70mph giving a piston speed # of 7314.5 @ 70 mph. Note: This would be easier if I'd just find specs giving rpm @ 60 somewhere but oh well, or better yet drive the car @ 70 mph and read the tach . So these #s are just from specs I found at cars.com, but they seem to jive with what I remember seeing when I drove it last.

It has been very good on gas so far. With my wife driving her normal way she has had some 44 mpg trips (about 20 mpg better than her taurus averaged), not bad for an automatic that isn't broke in yet.

Edit: the final drive i spec'd above is for the stick, the auto is 4.435. 5th gear is exactly .525 in the auto giving 1889.2 rpm @ 60 mph and 2204.1 rpm @ 70 for a piston speed # of 7493.8.

[laseradam]

I have had a new 5spd toyota Corolla for about 1 and a half months. I just am learning hypermileing so I am FAR from being good at it.
I was originally wanting to buy a VW TDI of some kind but the price people want even for used cars changed my mind.

I have gotten 2 47mpg tanks in a row with 30% city and 60 % hwy. The only mods are 36psi in the tires and a scanguage. The temps around here have been 90+ deg. EVERY day since I purchassed it. So I had to use the AC some.
I think I should be able to break 50 mpg tanks once the engine is broken in and the weather gets cooler.

Since I have a scanguage I will see how many RPMs at 60MPH and report back.