3.08 Gas Mileage

[x3speed]

What kind of MPG are people seeing.g with the 3.08 and a broken in engine?

[nickvrebel]

That's a loaded question.

There is a huge difference between:

*Reg. Cab Short Bed vs. a Crewcab

*Different engines available

*4 speed or 6 speed transmission

[Wolfmanjohn]

Is the motor just broken in or broken in and worn in? I've never seen my top mpg in any GM motor I've owned until it hit ~25-30k miles.

[x3speed]

Okay let me clarify 5.3 liter engine 6 speed transmission engine fully warn in at 25,000 miles

 

Extended cab

[vkjohnson]

2010, 5.3, 4x4, 6 speed, crew cab, 3.08

With a heavy foot and need for speed I averaged 16.5 according to the DIC with 70% highway miles. My mpg at 70 mph was around 18. 80 mph was 15-16 mpg. Just put a Max Energy Econ tune on though, and in this first week I've bumped it up to 21-22 mpg at 70mph and 18-19 mpg at 80 mph. Pleased with that to say the least.

[x3speed]

Thanks. How much is that tune?

[vkjohnson]

Thanks. How much is that tune?

 

 

I just bought it used from another forum member for $100. I think new it is around the $300 range. They've got a higher performance one too. Check out hypertech.com if you want to learn more about it. Only had it on for a week, so it may take some more time before I get a good read on what my actual mpg increase is. They advertise 2-6 mpg gain, so prolly closer to 2.. I think one of the big changes it makes is to the torque converter settings.

[x3speed]

Thx for the info

[uh6tdrvr]

When my truck was stock (and was till about 21k) with the cruise at 77 tonneu cover on the interstate I could maintain 19+ MPG and could keep it around 70 it would get 20. But mine is a CC 4WD with 3.42's