Gas Mileage

[Squid]

I just bought my first diesel truck over the summer--a 2006 GMC Sierra 2500HD with the new LBZ Duramax and 6 speed Alison transmission. When it was stock, I got 22 mpg at 60-65 mph. Within a month of buying it, I put on a leveling kit to level the front end out with the rear (about 2.5" of front end lift), trashed the stock 245/75/16 "doughnut" tires and put on some 285/75/16 treads. Since it is now less aerodynamic and is turning the heavier tires, I'm now getting 18-19mpg at 60-65 mph. In towing a 32' Wellcraft center console, I recorded around 10-11 mpg. (Not sure the exact weight of the boat as it was a friend's.) The easiest upgrade to increase your mileage is a programmer. This is an electronic unit that you plug into your truck underneath your dash, push a few buttons and unlock added horsepower, torque, and more gas mileage. The only problem with them is that when you do that, the onboard ("DIC") fuel mileage readout is way off along with the total fuel burned readout. I know this is the case with the Chevy's and GMC's....not sure about the Ford's and Dodge's. I have a suspicion about the Ford's since I have a friend who has 35" tires on his F250 and his computer is saying he's getting 27mpg. Again, not sure though. The only way to figure it after you install the programmer and even before you do is to hand calculate it and not rely on the DIC. For example, my DIC was showing 15.8mpg on last fill up however when I hand calculated it, I got 18.4. (This is without a programmer on my truck.) Hand calculated results after a programmer on GMC trucks seem to be around 24-25 stock and 21-22 with the 285 size tires like mine. The programmers can unleash a LOT of horsepower (upwards of 150+ hp) and torque (150-200 ft.lbs) so you just have to make sure your transmission will hold that much additional power. My GMC won't, but it will hold an additional 65hp that can be added with a less aggressive program. I definately think you cannot go wrong with the diesel truck---has been the best one I've ever had! I've also found a very good diesel forum on the web that answers a TON of GMC/Chevy diesel questions. The address is: http://dieselplace.com/forum/index.php Hope this has been some help and I didn't confuse you!

[Ozimo2]

I've got a 97 Dodge 12v Cummins that with a 12,000# horse trailer gets 12 mpg. Unladen I get 17. That's with 235/85R16 Kelly CSR tires @ 75psi year-round. That truck has 218,550 miles on it since the overhaul @500,000 miles!

I've also got at 00 Dodge V10 that gets just about the same base towing mpg and slightly better highway mileage. The bad news it needs premium gas, but up in the high country I can only buy 88 octane.

[anthony]

I've got a '02 Dodge Ram with 4.7L gas, 20" wheels...has been a great truck. The only boat I have to tow is my duck boat (19' Carolina Skiff) and the truck doesn't even know it's there. I get about 20 on the hwy and 16-17 around town. I have towed my dad's boat with it (6000# boat) and got 12 mpg going down to Hatteras, which I thought wasn't bad with a small V8. Thinking about buying a new truck now and trying to decide if I want to go with diesel or gas this time...think I am going to stick with gas since I don't have to do any heavy towing.

[Ozimo2]

That's the funny thing about it. I do heavy towing and the V10 is superior in every respect to the diesel, and I love my Cummins. It's just so much easier to deal with the gasser.

[johnseafood]

Toyota gets 26 miles to the gallon and the 2003 f-250 with 7.3L powerstroke gets 22

[Talbot29]

Wow! That's a lot of great information. I still stuggle with the total cost of ownership thing. My Suburban tows great - I'm sure it's not quite up to a diesel but it's damn nice. It sounds like the Cummings is the engine to beat - it's a shame on how they package it. It still seems that they is a fairly broad range on everyone's results.

Do hills have an impact? I know when I'm towing on the flat, my mileage jumps dramatically. It can jump up to 4 mph just by driving in the flatlands. I'm sure I could get much better mph if I didn't drive with a lead foot - but it's hard to teach on old dog new tricks...

[hotrodmarlin]

Once you go diesel, there ain't no going back.....
I traded in my loud ass 2002 Dodge 3500/Cummins dually (after 2 transmissions) for a Chevy 2500 Duramax/Allison transmission. I got 19mpg highway on the Dodge and about 8mpg pulling my 27 Contender. In my Chevy, I get 18 on the highway and about 10 pulling the boat. I was hoping I would get more out of the Chevy and I'm thinking about getting a chip.

[Ozimo2]

I hardly ever drive faster than 65, even when I'm allowed to, it just wastes precious fuel. And, at last Summer's prices!

[flatbottom]

2004 dodge 4x4. 4.11's straight 6 stock. long bed. weight 8000 lbs aerodynamic as a brick. Pulling boat 5500 lbs @ 55 15mpg

Not pulling boat @ 55 22mpg

These are (95) mpg

City stop lights reduce mpg considerably

The last tank results

A mix of stop and go. Some interstate and some rural roads. This tank taking it easier than normal. No run an gun, smelling of tires peeling.......so far 19.2 for 328 miles in a mix of driving situations. Once a pedal stomper to get grandpa away from the tail gate and fill his windshield full of unburned full, just once though

[jpd~]

Around here regular unleaded is running around $2.50 a gallon, and diesel $3.10. Since diesel costs approx 25% more, 15 mpg on unleaded costs as much as 18.75 mpg on diesel.