LMM mpg? - Page 35

**rmcable** · 11-03-2009, 12:18 PM

really I did see an increase in mpg. It looks like Im getting about 2 mpg better than stock setting. Im not sure if it was really the Edge or if it's just the fact that my truck has more miles on it. when I bought it new I was seeing 10.5 to 12 mpg in town and 13 to 15 highway. I am now at 18 to 18.5 (hand calc. w/edge) highyway. (16.5 to 17 stock) Town Im not sure I really haven't ran enough in town miles to get proper numbers.

x2desmit · 11-03-2009, 06:02 PM

Quote:

Originally Posted by rmcable

really I did see an increase in mpg. It looks like Im getting about 2 mpg better than stock setting. Im not sure if it was really the Edge or if it's just the fact that my truck has more miles on it. when I bought it new I was seeing 10.5 to 12 mpg in town and 13 to 15 highway. I am now at 18 to 18.5 (hand calc. w/edge) highyway. (16.5 to 17 stock) Town Im not sure I really haven't ran enough in town miles to get proper numbers.

I've only seen about 1 MPG on average with the Evolution. But it's unlocked so much power, without sacrificing gas mileage, that I don't care.

8racer, you get 14 on the interstate?? What speeds do you drive?

And I'm kinda confused on the varying gas mileage reports from people. Does anyone think these different numbers could come from the actual manufacturing of the engine, and every engine ends up being different?

**dhaile** · 11-03-2009, 06:48 PM

Quote:

Originally Posted by 07LMM

Just got home from a trip to South Fork, Co. about a 1200 mile round trip. Pulled a 28ft 5th wheel with 2 slide out not sure on the weight.. Got 15mpg on the trip. Have 8300 miles on truck.

What the? How are you doing that? Downhill? Hand calculated? I have not approached anything over 11 pulling a load like that!

**rmcable** · 11-03-2009, 07:03 PM

Most are highway miles
And yes I believe some mileage variations are from manufacurer. I have 5 other trucks with 5.3 gasser and a few get 15 city and a few only get 12 to 13

I haven't checked mine with a tow yet

8racing · 11-03-2009, 07:58 PM

i can get a little better then 16 mpg on the highway at 70mph. but i get around 14 mpg on a tank when i go highway then bump around in town. thinkin about a programmer and exhaust.

garys08slt · 11-03-2009, 08:37 PM

I run the crap out of mine all the time since it was new, it now has 43,000 and i tow pretty frequent .I bury the spedo. the thing-a-ma-jig on the dash is telling me 13.5 . I dont think anyone else could do worse

setexan · 11-04-2009, 07:05 AM

Quote:

Originally Posted by Hook'em_Horns!

Your Lmm And Confirmed Mpg Fix!!

I tried the link above and it didn't work for me. I have deleted the dpf added a programmer (S2) and my mileage hasn't seemed to improve. If the confirmed fix is still valid can you tell me how to view it or what it is.
I have kept every fuel receipt and calculated my mileage from new. The best I have ever gotten was 18.6 for ONE tank and then took the truck in for warranty work and they reflashed the ecm. I have spent about a grand trying to improve my mileage. I’m not sure my mileage will ever improve enough to make the upgrades cost effective but, on a side note I have to say that the MBRP exhaust does sound pretty mean.

I’m not trying to highjack just trying to improve mileage so, I do apologize. If I can figure out how to insert a spread sheet I could show my mileage from new on here through various driving conditions.

**Hook'em_Horns!** · 11-04-2009, 10:46 AM

It (link) does display strange...let me check it.

Your Lmm And Confirmed Mpg Fix!!

**Hook'em_Horns!** · 11-04-2009, 11:02 AM

Okay, it was deleted.

This is the jist of it here...

Quote:

There is a bulletin on " Diesel smell on regenerations " ….gm has found the turbo outlet pipe or down pipe is leaking right off the back of the turbo due to a flaw in down pipe production. This is causing an estimated 2 mpg loss in fuel mileage. There is only 2 ways to see if its leaking, remove the turbo shield and look for black soot around the band clamp at the turbo down pipe. Or gm has an exhaust pressurizing tool that puts pressure into the exhaust system checking for leaks.

I hope this helps anybody with an lmm motor. If you take your truck to the dealer just tell them that you smell diesel in the cab of the truck mostly during regeneration. That should trigger the tech to look for this bulletin. It DOESNT SAY anywhere in the bulleting that is tied to low fuel mileage. Therefore, DONT go in their complaining about that.

And from someone who had it replaced...

Quote:

I was driving my truck today for the first time since I had down pipe replaced and to my surprise I was for the first time getting over 20MPG, yes-20MPG running 55-57 MPH on a country road that was mostly a up hill climb to beat all.

Something to look at on your LMM anyway.

setexan · 11-04-2009, 11:20 AM

Thanks HH

i guess it doesn't apply to me since my DPF and Cat fell off.