LMM mpg?

[LMM.L]

I did the delete and was pulling a 5er for part of the time over the weekend and still got 14.5 mpg. Before the best I EVER got empty was about 12.5.

[BIG R]

I have a 2008 LMM chevy and am averaging about 13.5 in town and 16.0 on the highway. I'm thinking about putting a performance chip in it but someone said GM can now tell starting with the 08 models that the truck was chipped. Has anyone else heard that?

Also was wondering what chip everyone is running? I had an 06 durmax before this truck and had it chipped with a Bully Dog. My performance was greart and fuel mileage was 22 mpg on the highwat at 75mph.

Any feed back would be appreciated.

[Meyerperformance]

i run quadzilla stealth 2, and they can tell if the ecm has been reflashed. so if you wanting to keep dpf i would do a edge juice with attitude or ts mp8. I would do the dpf delete if not worried about the warranty.

Tyler

[LMM.L]

Originally Posted by BIG R

I have a 2008 LMM chevy and am averaging about 13.5 in town and 16.0 on the highway. I'm thinking about putting a performance chip in it but someone said GM can now tell starting with the 08 models that the truck was chipped. Has anyone else heard that?

Also was wondering what chip everyone is running? I had an 06 durmax before this truck and had it chipped with a Bully Dog. My performance was greart and fuel mileage was 22 mpg on the highwat at 75mph.

Any feed back would be appreciated.

Wow that's great for a stock LMM. Welcome to the site, I think you're right they can tell, but unless you mess something up by over doing it and try to get it fixed under warranty they probably won't mess with you.
I run EFI Live, don't really understand it yet but I know it will work great once I get the hang of it. It just takes time to learn like all things.

[codyn]

we just got done with a dpf delete and it is getting 24 mpg highway hand cal.

[Big White Dmax]

My 08 LMM is far far better on fuel than my 05 F350 V10 and better on fuel than my 04 6.0 F350 so I am extremely surprised that a 7900 dual wheel pickup can get 13 in town and 18 on the highway per good old US gal. I am Canadian but I convert to US gal. on these forums.
The LMM will burn more fuel when doing a regen but to me it is worth it to have a sweet smelling diesel pickup. My wife, like many people, is made sick by diesel fumes. She suffered through my 95 and 2000 PSDs and then in 04, the the Navistar 6.0 came from the factory with a sweet smelling exhaust. I had heard horror stories about the PSD 6.0 but really wanted an engine that did not bother my wife so I bought one. My 04 turned out to be a true sick-oh and after the third haul in with plugged EGR, they reflashed it. It now stunk worse than my previous 7.3s and still had poor mileage. I ordered my V10 gas. Trucks are like women. Give me a sweet smelling gal with good manners and even if she costs me a little more, I will take her over a smelly pig with poor manners even if the pig is cheap to keep. This to me is the same comparison between a Dodge and a Chev. Chev ....classy . Dodge .......cheap.
Sorry to offend but this a GM forum.

[LMM.L]

Alright, I just had my first trip with no trailer after the delete (my truck sits around alot) and to my amazement I got 18.5 mpg hand calculated. Thats up from the 11 to maybe 13 mpg on a good day. What a difference!!! Now the only problem is the tune I have in is causing my transmission to slip under heavy acceleration.

[BAD]

I now have 1343 miles on my 2500HD LMM and I`m getting 15.1 mpg in the city

[Coker6303]

Do not judge mileage by the trucks information center. Always hand calculate for accuracy. The information center can be off as much as 3mpg.

OOOPS, thanks jrc371...

[jrc371]

Was the LBZ the motor for the 4th quarter of 05 until the 2nd quarter 07 and then it changed to the LMM?