Realistic MPG with a Dmax 6.6

[WayneJessie]

I'm considering a 06 2500 4X4 with the Dmax/Allison combo. What are some of you realisticly getting MPG wise with these trucks empty? Thanks

[6.0vortecchevy]

My buddy got 16 city and 20 highway with his.

[BC Rod and Custom]

Dad's truck - Edge Programmer set to level 2, cold air intake, Amsoil Filter System, 5 inch straight exhaust. 22mpg highway with 285/75/16 on stock wheels.

[Mark13]

I see mid to high teens around town or cruising at 55-60 on country roads. I'll see high teens to really low 20's on the highway at 65ish. I get about 8-11mph pulling my 28' trailer.

Mods: 4" straight pipe, factory intake opened up. Efi-Live on +85hp economy (I'm going to try my race tune on the next hwy trip to see if it's better). 4" cognito lift, 285 tires. Truck weighs 8400lbs.

[andy howell]

my bone stock '02 4x4 ex cab gets 18 anyway you drive it empty. loaded pulling a car trailer gets 14.
andy

[Snotrocket]

An unrestricted exhaust setup will get your most initial bang for your buck as far as MPG goes.

[DarkCharisma]

I've averaged about 14MPG over the last two tanks. That's 20/80 highway and city driving, with 10-15 min. warm-ups each morning. In the summer, it was a little closer to 16. Part of that drop is probably attributed mostly to warm up times and winter blend fuel, but I did go from a 275/55R20 to a 305/55R20, which is much wider and probably a little heavier.

When I drive strictly highway and set the cruise at 75MPH, I have repeatedly been able to achieve between 17-20 MPG on the same trip, wind conditions permitting.

[Chingon HD]

Anyone getting in the 22-26 range?

[DarkCharisma]

Anyone getting in the 22-26 range?

22 can be done with the right tune, gears, tires, atmospheric conditions and proper driving conditions. Anybody getting over 22MPG regularly is either lying to you, or has every variable correct, and a very good right foot.

[neubauej]

My 06 RCLB got around 17 town and 23ish @70-75. That was with 265/75/16's, 3.73's mbrp exhaust, and a predator hand calculated. The dic claimed mid-high 20's all the time, if i puttered at 55-60 it would show mid 30's, but it was lying..

[JustinSilverdo]

The older trucks LB7 01-early 04 get the best fuel mileage, I usually get 17mpg in town driving like I stole it, and 22-23 highway thats with 33" tires and a 500 rwhp tune, I have a few buddies with LBZ's 06-07 stock your gonna get somewhere around 14mpg in town and 18-19 highway, if you go with a mild EFI tune or a mild handheld you should see 16-17mpg in town and close to 22mpg highway, it all depends on your foot!!!

[JustinSilverdo]

My 06 RCLB got around 17 town and 23ish @70-75. That was with 265/75/16's, 3.73's mbrp exhaust, and a predator hand calculated. The dic claimed mid-high 20's all the time, if i puttered at 55-60 it would show mid 30's, but it was lying..


The DIC always lies!!!

[rebelbowtie]

The DIC always lies!!!

No it doesn't, people just add aftermarket tires or change gear ratios and never calibrate the speedo. Even hand calculating can return false info. In both my 2004 2500HD amd my 2008 Audi A4 the DIC or MMI in the Audi consistently return accurate data. When compared to hand calculations they were around 1mpg +/- actual average.

[JustinSilverdo]

No it doesn't, people just add aftermarket tires or change gear ratios and never calibrate the speedo. Even hand calculating can return false info. In both my 2004 2500HD amd my 2008 Audi A4 the DIC or MMI in the Audi consistently return accurate data. When compared to hand calculations they were around 1mpg +/- actual average.

Even calibrating the tire size with EFI I have a couple 03-04 trucks tuned that are claiming 27+ mpg, you must be lucky with yours? Its a good reference but not accurate.

[rebelbowtie]

27+ average or "instant" economy. I noticed the instant economy was always waaay off on my truck. But the MMI on the Audi is pretty advanced and displays AFR. That's the best tool for getting mpg's IMO.

I am sure with EFI Live someone could get the DIC to display that info though.

[DarkCharisma]

Drove round-trip to my brother-in-law's motorcycle race today (Cow Dung Seasonal 2011, Expert/Unlimited Class--he won!) through a nasty cross-wind the way down. The way back was a lot nicer... fresh tank of diesel, averaged 13MPG on the way down and 19MPG on the way back, to give me an average somewhere around 16MPG.

So, conditions hurt a lot. I didn't push past 70MPH with the wind and never above 75MPH once things cleared up.

Just a little real-world report when things aren't always ideal...

[farmboy575]

our 2001, 3500 gets 21, our 2005, 3500 gets around 16 but its a service truck, both of our 2006, 2500HD get around 19, our two 2011, 3500 get around 19 and about the same for our 2011 Denali HD

[DarkCharisma]

I've never heard the LML's getting over 16. People have HORRIBLE mileage claims over on duramaxforum.com with the '11 models. Is that hand-calculated, and are you averaging in Regen?

[Koots]

DPF kills the mileage. Most will see an average of 14MPG And not much higher than that even under ideal conditions.

Funny to think that the process to clean up the exhaust, drops the MPG so significantly...which causes more em missions I would imagine. LOL

[farmboy575]

its just hand calculated but they dont get horrible mileage at all. they only have like 4000 miles on both of the duallys but the denali hd had 20000 and thats right around what you get hand calculated

[Pre-StrokerC150]

I have a 2008 2500HD with a 6" lift and 35" tires. I still have the DPF and I only get 12-13 on average with a stage 3 Hypertech tune. I get about 10-11 towing a 6K lb trailer.

It doesn't make sense to me either regarding all the additional fuel to "clean up" the air.

Sound like f***ing for virginity if you ask me.