What's the best mileage have had with the lmm by checking at the pump I've been tuning my dads 08 and just built a new tune for it tuesday nite and put it in yesterday morning when he filled up to check the mileage we drove it around yest to a couple jobs and then today most of the miles was country rds running 65-70 and some thur town stop n go's we went 312 mile on only a Lil over a quarter of a tank. So we stop to filled it up and it on took 9 gallons even so I walked by in and asked the cashier to turn the pump back on to make sure it was really full and it only took seventhy something cents it was .171 gallon so on 312 mile it only use 9.171 gallons which equals 34.02 miles to the gallon I couldn't believe it cause I was excited at 21.9 which was what it was showing on the dash. My dad is happy as hell and he don't want to take it out but I'm really happy with this tune.

 

You people figuring the milage based on miles driven divided by gallons to fill up, or just looking at the display? In my experience the computer is overly optimistic, yours might be ok, probably oughta check if you haven't already.

 

[QUOTE=rocko cummins;877231]
What mods have you done to that truck?

 

I bought my truck 2 years ago, it's a 2007 1/2 LMM. To my knowledge the engine is stock. I do have 20 inch rims, approx. 6 in lift kit on it and a cab height camper shell.

 

With the changes I've made to my truck, I'm getting about 15mpg in the city, and 20ish on the highway. Keeping in mind I do not speed, and the speed limit in most of Canada is 60mph. I have gotten as much as 24mpg strictly highway on flat surface, no wind, no load. That was two hours at 60mph with the cruise set, and not much for hills. Still, the tuner, exhaust, air intake makes a big difference. Driving habits make more difference in how your truck will perform when it comes to mileage than most things. IMO.

 

MY '09 2500 CC SHORTBOX 4X4 STOCK ENGINE GET 9MPG LOADED PULLING A 24 FT ENCLOSED TRAILER LOADED TOO.ABOUT 1500POUNDS ON THE TRUCK AND 10,000 POUNDS WITH THE TRAILER. DON'T BABY IT AND DRIVE 70-75MPH WHEN WEATHER PERMITS. DONE THE 1400 MILE TRIP SEVERAL TIMES BETWEEN IOWA AND ARIZONA AND MILEAGE DOESN'T VARY MUCH. RUNNING EMPTY I'VE GOTTEN AS GOOD AS 14MPG. THE TRUCK HAS ABOUT 120K ON IT AND ITS THE BEST TRUCK I'VE EVER OWNED.