New Car Comparisons

[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.

[GasSavers_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...