Diesel
 

I am looking to buy a full size pickup. I would like some advice on wether to go for a regulas gas engine or diesel?
I've been looking at the Chevy 2500 model.


Andy S.
Vero Beach, FL.

I can't speak for Chevy, but my ford diesel has been a huge disappointment, mileage-wise. My 5.0 gas V8 (Chevy) and 4.3 gas V6 (GMC) got better mileage than the 6.0 diesel (Ford). Chevy's 6.6 liter diesel probably gets worse mileage than the Ford 6.0.

Save your money and buy a gas powered truck with a V6 or small V8.

Back in the mid 80's I talked to someone with a Chevy diesel. I think it was a 1500 series. He got 35mpg at 55mph with no load.

Yup, the old diesels were good on fuel economy. Then the horsepower race started. Every production diesel truck is turbocharged and intercooled, AN you can't get a fuel economy axle. The tallest axle offered by the big three is 3.73. Is this progress????

I was considering a ring and pinion swap for my F350 to say, the 3.23, a 3.42, or a 3.55, but you can't buy one, even from the aftermarket.

Do all the new trucks have overdrive? The old trucks didn't? In my opinion the newer ones are detuned. They can still tune them to get better FE and still pass emissions. I've talked to engine tuners, they can tune for better FE but they make the final decision

Yup, all of them have overdrive, usually about .7 ratio. but it's not enough to keep the RPMs down. My engine is still spinning 1900 RPM at 70 mph.

The truck really doesn't need such a short 3.73 ratio. It has a 5 speed automatic that would give plenty of off-the-line power with a 3.23. you have to wonder why they don't even OFFER an economy axle. You can buy a 4.11 for better towing, but no shorter ratio than 3.73.

They make afterket FE chips for truck, but I'm afraid to put one in for fear of voiding my warranty.

1900rpm at 70mph is nothing, are you sure you don't mean 2900rpm?

edit: forgot, diesels rev lower, huh?

Yup, redline on direct injection diesels is usually about 4000 rpm. Turbodiesel make gobs of low end torque, so 1500 rpm at 70 mph would be right in its power band.

I've been looking for a full size truck too, to replace my fuel-swilling 79 F250. I don't use it that much, but enough that it would pay to get a truck with decent mileage. I'm thinking of an early 90's chevy 1500 WT, or maybe a manual Ford inline 6 (less mpg though). I'm still not sure if a 1/2 ton would cut the mustard, but they did improve them a lot in the 90's.

Diesels have a couple advantages: they work well at high altitude, and they get better mpg at high loads (big trailer, lead foot). They also have higher resale than gassers, but routine maintainance is more expensive. The other advantages of long life and generally high mileage don't really apply anymore, due to the horsepower race. The first round of direct-injection turbos were probably the peak: the 12-valve Cummins dodges, the 6.5 chevys, and the 7.3 fords.

BTW, you can try https://www.ringpinion.com/ for gears. I don't know what sort of axle that has, but for example they have a 3.08 for the 10.25" ford.

I just bought a new 2006 chevy 3500 Silverado crew cab 4wd dually last week. It has the Duramax 6.6 deisel linked with the allison 6 speed auto transmission and a 3.73 rear end. The day I pulled off the lot it averaged about 11 mpg. After freakin/wiggin out for a day, I went to a deisel forum and found out that most Duramax's start out with poor mileage and get significantly better mpg after about a 5000 mile break in period. Sometines it takes longer. Most of the guys stated somewhere around 20 mpg (hwy) for the Duramax/Allison 6 speed combo after break in. I am now at 1500 miles and my mpg has increased to 17.5. I expect more after 4,000 more miles of driving. In addition, I just ordered twin hydrogen fuel cells ($675 each)that claim a guaranteed 31%+ mpg increase. I hope to get to 30 mpg with that and a couple of other mods.
That having been said...I love this truck. Way powerful, very quiet, and very smooth. GO WITH THE DURAMAX DEISEL! There really isn't a better deisel out there right now. Do your homework, you'll see for yourself.