Duramax, what's the best gas mileage chip or programmer???
 

I've got the 2004 Duramax 6.6 turbo diesel and I've talked to a few guys that said they were getting 22-24 mpg. One said something about Bullydog and can't remember the other. To make this easy, I don't believe it!! Best I ever got was 17-18 mpg, but usually average 16 mpg. I have the Hypertech programmer, great power gains for the money, but no where near 22-24 mpg. Am I missing something??

Re: Duramax, what's the best gas mileage chip or programmer???
 

Change your air-filter

Re: Duramax, what's the best gas mileage chip or programmer???
 

Nope, it's all BS. Any possible gains made by the programmer will be outweighed by your suddenly heavy right foot.. :drink:

Seriously tho, I can get 20 mpg on the highway at 65mph, and 16-17ish combined driving. That's about as good as they get. I've got the predator programmer, Boost stick, Cat removed, egr blocked, and a cold air intake.

The programmers throw the computer mileage calculator on your dash waaaaay off, and that's where most people think they are getting better mileage. Checking it by hand will confirm the ugly truth.... :(

Re: Duramax, what's the best gas mileage chip or programmer???
 

Got a 03 Crew Cab DD 2wd and the best I have ever gotten was 18 mpg. I am convinced that the typical owner cannot do simple math and really believes that a 300 HP truck that weighs over 3 tons and punches a 48 sq ft hole in the wind gets 25 mpg! Simple math folks, 20 gallons to get it back to full and 360 miles travelled is 18 MILES PER GALLON!

Re: Duramax, what's the best gas mileage chip or programmer???
 

I did... I bought the "Green" filter. Suppose to be the best out there.

Re: Duramax, what's the best gas mileage chip or programmer???
 

2004 LB7 or LLY??

www.pmtdiesel.com

Re: Duramax, what's the best gas mileage chip or programmer???
 

I have 2002 3500 duramax, i've been getting 20-23 mpg on intersate running 80-85mph, no BS. I would'nt have beleived it myself. I have the quadzilla programmer that will take it up to 215 extra hp, airraid intake, 4inch exhaust. I have got it set on 165hp, dont wont to go to high without doing some tranny work. This chip also calibrates speedomter with your tire size, and takes off the top end limiter. Not only did it improve gas mileage its fun as hell to pull up beside a mustang and drill it in a 8000# truck. I would recommend this programmer anyday.

Re: Duramax, what's the best gas mileage chip or programmer???
 

I have a 03, 4 wheel drive that I average 19 and I drive 80-85 most times. When my friend pulled my 42 cat to florida he got 17, then drove from for St Louis to tulsa and averaged 21. I would not have believed it either but there were two trucks and 4 guys who all ckecked it.
I have the bully dog programer, Intake and 4" cat back exhaust. I think you have to have all three because while I was waiting on the exhaust, about 2 wks with the other mods, It didn't get as good or run near as good. Also I do have a hard bed cover.

Re: Duramax, what's the best gas mileage chip or programmer???
 

2003 cc dually 2wd lowered down with the mac airfilter 5"exhaust kit aero turbine muffler running the quadzilla tune at 190hp setting going to florida running a constant cruise setting at 77mph I got between 21 and 23 the whole way there and back with the truck loaded with gear, no trailer and a hard be cover on it, this is hand calculated no dic numbers.

Re: Duramax, what's the best gas mileage chip or programmer???
 

2002 K3500 crew cab with the allison trans.-the best I've gotten has been 19 mpg on the highway light load and driving 65 mph. The truck is stock. It looks like you can get in the 20 mpg range if you have a two wheel drive.

Re: Duramax, what's the best gas mileage chip or programmer???
 

Father put the edge system on his in FL last year. He towed his 28' Colbalt down without the chip, and towed it back with the chip. He told me he noticed no difference in fuel consumption! But the ease of towing was greatly increased!

For what thats worth.

Re: Duramax, what's the best gas mileage chip or programmer???
 

C J has the reality...
My fuel milage certainly didn't get better.

Try chacking your ODO against a GPS boys...

I have 285/75-16 tires, and yes, I used the predator to recalibrate the speedo for the big tires. It's still 8-10% off. I travel about 5 mph faster than what reads on the dash.

So, I fill the tank....
add 10% to the milage that the ODO says I traveled, then divide it by the fuel it takes to fill it back up...
No better than 15-17 boys... :mad:
I can get the dash to read over 20 on a long highway run, but she ain't getin 20...

I have a AFE stage 3 intake and the Predator set on the 65 hp setting. Yes, I know I should put a bigger exhaust on it. It will help fuel milage...but not 5 mpgs... :rolleyes:

I never believe anyone that says they get more than 20 mpgs..
I guess a 2wd 3/4 ton will get 20...


FYI the new LBZ 4x4 dually (stone stock) we have got 11.5 on the dash over a 1500 mile pull with an empty 5,000lb boat trailer. 10.0 with a 14,000lb load.

Re: Duramax, what's the best gas mileage chip or programmer???
 

Taller,more aggressive tires WACK your mileage even after correcting for their added dia. My winter tires are 5 % taller than stock but knock my mileage down 10-15%,Smitty

Re: Duramax, what's the best gas mileage chip or programmer???
 

I have a 2005 Chevy 4x4 2500hd duramax ext cab 265 series pro comp allterain load range E tires (recaled the speedo & seems to be right on). I seem to always get about 14.5 - 15 mpg. It doesnt seem to matter if im empty or towing a 33' or anything inbetween. I like the power difference too compared to last tow vehicle. A 2000 late model suburban 4x4 2500hd with the 6.0. The fuel milage is better and is consistent.. Jamie

Re: Duramax, what's the best gas mileage chip or programmer???
 

2002 GMC 3500 4X4 Crew Cab Dually, totally stock.
Worst on a tank 13 MPG
Best on a tank 19 MPG
Average for 19,000 miles, 15 MPG

Re: Duramax, what's the best gas mileage chip or programmer???
 

I read about a test where the same vehicle (do not recall the vehicle) got between 13MPG and 23 MPG with different drivers.
If you want to improve fuel economy keep your foot out of it. I have 2004 DD and best ever was just under 24 MPG (bone stock) granted I was 5 hours on the interstate at about 62 MPH. Keep the RPM's under 2grand for a tank and see what you get. I am almost always at 19-20 empty. 30K on engine.

Re: Duramax, what's the best gas mileage chip or programmer???
 

I agree with DONZI33 I have the same thing and that is what i'm getting. By the way had a 2000 3/4 ton sub as well and this is a huge diff just having the power I want to tow :D

Re: Duramax, what's the best gas mileage chip or programmer???
 

My stock 2500HD with the LLY Duramax is getting 22 on the highway consistently, and 17MPG around town short trips. The Driver Info Center (DIC) is dead on accurate with the manual calculations.

From what I've been told, a chip won't help but you can do things to reduce your drag like installing a fiberglass tonneau/lid on it and staying with the gawd-awful looking skinny stock tires. Stay light on the foot, you'll see similar numbers.

The Diesel Place is a very good source of GM truck related info.