My dad got a 05 dmax a few months ago and traded in a 02 dmax. he said the gas mileage in the new truck sucked compared to the 02. both trucks are stock except for banks exhaust and the 05 got the cat hacked off. could that be the problem or is it just the 2 different motors?

break in? did he have the lb7 or lly i don't know if the lb7 was available in 02 but it could have been.

There are some LLY owners that complain of their mileage and some that don't. But I've also heard that the LB7 gets better mileage than the LLY. I hand calculate pretty much every tank and average about 16mpg mixed city/highway and about 17.5mpg on strictly highway (but I usually keep it around 80+/-mph). If I drive the speed limit it's usually around 20mpg.

I didn't think dmax's got good "gas" mileage. Sorry I'm a smart ass.

No they get great "gas" milage, they don't use any gas at all. lol, just kidding around.

my old man has an 03 with an lb7 in it. around town he would get like 15 mpg and on the highway it would step up to like 17-18.

he bought an edge module, and around town went up to like 17-18 and hwy is now 20-22

towing an enclosed car trailer ( one heavy ass brick ) it used to be 10 mpg, now with the edge it's 14mpg

oh, btw.... all this mpg is with the edge in stage 2.

it keeps turbo spooled up at lower rpms when going up long steep grades with the trailer, it never downshifts anymore, ever!! it doesn't need to. This edge module has paid for itself already, as you can imagine.


oh, and btw..... ridiculous smoky 1/2 mile burnouts in stage 4 are just awsome. 14.7 quarter mile times for an ex cab 2500hc is just...... well, amazing. Get an Edge!!! i dont' remember who i bought it from on here, but thanks a ton.

Diff in the LLY and LB7? My step-dad is looking into getting a used d-max so Im trying to do a little homework for him.

my uncles d-max is whatever year the first ones where and it gets like 22mpg and runs low 9's in the 1/8

I have an '04 2500HD with the LB7 and just made an 1100 mile round trip to Vegas and back (unloaded) and got about 20 mpg for the trip. which is not bad considering I was doing 70 - 80 mph.

A friend of mine has a 05 LLY with 6000 miles and is getting about 10-12 around town. He is not to happy about it and GM is offering no help.

What is everyone else seeing with the LLY? What kind of milage improvements have you all seen with tuning of the 05's?

one of my customers has an 04 lly and usually gets 10-12 highway with an enclosed car trailer. he/we just added the k&n kit, and 2 modules with an egt. we will se how it does soon.

it is all in your gearing in the rear end ... my dad has an 04 lb7 and gets 14 average he has the 4.10 rearend ... i saw another truck same everything and it got 20-23 with 3.73 rearend ... there you go

diesels are built to such tight specs that they usually do get crappy milage till there broke in. The best way to break one in is tow a heavy ass trailer 1000 miles or so and put some strain on it. I know a few guys who picked up 2-3mpg after breaking it in good towing.

On diesels also getting a free flowing intake,exhaust, and advancing the timing all lower EGT's and increase "fuel" milage by allowing a more complete burn in the cylinder. My old cummins with 238,000 miles on it and 3 speed tranny got 23mpg on the highway an 20 in town.

he installed the egde box and a k&n kit. milage went from 10 to 13.8. he isgoing to montana on monday loaded one way and empty the other (28 foot enclosed trailer).
the track has 110k miles.

we also stacked an edge ad an md-8 on a '04.5 cummins and found a ton of power.