Well, he got one. He is only getting about 12-13 in town. Last weekend he said the computer said he was getting 9 pulling his 32 foot fifth wheel with a head wind and on the way back two days later on the same tank it was up to 14 with a tail wind all of the way back. I know he would spent twice as much on fuel with his old truck. He left yesterday to camp about 325 miles away, so we will see a real test for it.
I told him he needs a tuner for it, but he asked the dealer when he bought it and they said no way so he will not do it.

Josh

Mileage
 

I have a 2007.5 Chevy, LMM, 4x4, cc w/8' that is completely stock and I avg 15.7 mpg.

My dads LMM gets around 15 all the time with 285s on it. My LBZ gets 18 most of the time, really depends on how much i put my foot in it

the Regen just kills mpg, i wastes too much fuel, you know that it wont send the truck into Regen mode if it detects that it doesn't have enough fuel in the tank?

there could be a few ways around that regen mode and still not even touch the puter

I know that some people are getting 18-20 mpg out of there LMMs so I know its possible

hey guys !!! im a new guy on this forum but i figured id chime in lol. I have a lmm with 22,500 miles currently on it. Mileage around town is about 16. Highway drivin is about 18 on short trips. If driven around 300 highway miles itll easily reach 21 in one trip. The least i ever got was 12 when i first got it and it went into regen when i 'was breakin it in' lol. hope this helps

Ok guys. I'm looking into buying a new LMM and I'm looking at all of the specs on several different trucks and I may have figured out one of the reasons people are experiencing such differences in fuel economy (if this hasn't already been said before). OK, these trucks come from the factory with different emission standards. I'm in Texas and I have in front of me 3 different trucks, all of which meet different emission standards: FE9 (Federal Emissions), YF5 (California Emissions), and NE1 (Northeast Emissions) which are very similar, I've read, to California's Emissions standards. Just curious if anyone out there's noticed if my theory might be true? I'm just figuring that more strict emission guidelines may lead to the poorer fuel economy some of you are seeing.

Delete the Dpf and you will see around 18 city or close i do but have a reg cab long bed but it is 4x4.

can the dpf be deleted with just a programmer or module? or do you have to replace the whole exhaust?

programmer, or efi live, then he will need to replace the dpf with a pipe