Fuel Mileage Tips

[nicholg2286]

Besides tire pressure and driving with a raw egg under the pedal, what are the best tips for getting really great mileage with a D-Max? I have a Sierra 2500 HD Crew 4x4 with 1800 miles on it. I am getting about 14 mpg with it. I'd like to think that I will get better, and I know that there are a million different products that promise to increase mpg, but which ones really work? Which ones are cost effective? Which ones won't have any effect on the GM warrantee? What tips can you guys offer?

I really appreciate the info!!

[rob from bc canada]

Avoid short trips - that'll kill you.

Stock mileage empty running 60-65 including a few stops and starts should be around 17+ US Mpg, on 100 mile or so trips.

So far, I haven't heard of any mods that will pay for themseves in fuel savings alone the medium term.

Kennedy has an economuy tune might get you one or two mpgs, but the cost is pretty high - need a spare ECM.

[DieselMonk]

short trips, lots of cold starts, stop and go in the traffic kills all your milage. Mine isn't broken in and I get about 13.5L/100km on the highway going about 110km/h, and about 18l/100km in the city.

[Mark Rinker]

1) Replace the paper OEM filter every oil change.
2) Run synthetics in the engine and in your diffs.
3) Let the Allison shift at low RPMs - play a game with your gasser-trained driving skills to see if you can go ALL DAY and never exceed 2200rpm.
4) Lose the cat if you have one. If you have CA inspection, gut the cat and leave it where its supposed to be.
5) Get JK's economy tune and ECM reflash to Federal emissions rather than CA emissions.
6) If you have and EGR equipped truck, do the blockoff plate mod.
7) Bump up your boost slightly over stock.

[up@12]

short trips, lots of cold starts, stop and go in the traffic kills all your milage. Mine isn't broken in and I get about 13.5L/100km on the highway going about 110km/h, and about 18l/100km in the city.

How many km on your truck? I have about a 1000km on mine and I am getting 16.2/hwy at 120-130 and you don't even want to know what I get in town. LOL

[DieselMonk]

How many km on your truck? I have about a 1000km on mine and I am getting 16.2/hwy at 120-130 and you don't even want to know what I get in town. LOL

620km. still have to break my 07 LBZ in. :D

[More Power]

When driving for fuel economy, keep one thing in mind.... 1800-rpm is a magic number. :) Doesn't matter whether you're commuting or towing a 15K travel trailer.

Jim

[SoTxPollock]

Mark about sumed it up, except I think replacing the air filter ever oil change is a bit concervative. Other mentions are don't add on extra weight nor wider tires, lower the front end as low as you dare. Just remember it takes energy to accelerate mass. The change in velocity from present speed to a higher speed is proportional to the rate of change. Simply put the faster you want to accelerate the more fuel is required. A diesel engine is full open to air, there is no throttle like a gasser. All else being equal it still depends on your right foot. Also in cold air temps run the winter front cover to keep temps up, they're right short trips will kill mileage.

[Mark Rinker]

True on the air filter changes - if you are running unloaded most of the time, in dry pavement conditions.

I have learned (the hard way) how dynamic air filter replacement on diesels is. Its not a function of MILES driven as much as its a function of CIRCUMSTANCES driven through. The amount of air filtered by a diesel truck that tows is many times that of a filter on an empty truck driven the same miles.

If you tow on a salt spray day - you may need a new filter when you are done. They load up with salt, dry out, get crusted and don't flow after that. Funny thing is, they still look white and clean.

If six months goes by before you replace that filter, you have wasted many gallons of fuel.

[SoTxPollock]

OH WOW, you are absolutely correct, living in Texas I don't have to think about salt, but lots of others do. Man I hate the thought of having to drive thru that stuff. I even hated to drive by the Bonniville Salt flats the last time I was by there just thinking about how much salt atmosphere I might be driving through. Filters are cheap, Duramax's are not.

[Mark Rinker]

Ahhh Texas. Nice state. I love Chris Rea's song of the same name...(sample here) http://www.mp3.com/albums/13136/summary.html

By the way, I have amended my previous post from 2500rpm to 2200rpm. I drove 400 miles today and never exceeded that, got 14mpg towing 5K trailer and it was -3F most of the morning no winter front to damn cold to put it on.

Now you know why I am dreaming of Texas this afternoon...

[Prestonia24]

I have nearly 7k miles on my 06 cc lbz. and on average ill get 17 combined freeway/street.

upon my last trip to vegas in december I did a test on fuel mileage.

on the way to: 290mi, avg speed 80-85mph. fuel economy (hand calc) 13.2mpg.

the way back: 291mi, avg speed 67mph (1800rpm). set the cruise control, even over the cajon pass. fuel economy 22mpg. made it on a half tank....
(before the pass the dic estimated economy was 23mpg, and its spot on)

moral of the story. keep it under 75 and save some fuel.

-Cam