Fuel Milage

[D.A.E.A]

We have a 2011 5.3l 2wd 4door with hard shell and 32,000 miles. We live in town And a normal mpg is 14 for in town weekly driving. Out
On the road it will get closer to 16. We have had two tanks get 19 right when we hit 30k miles and I think the stars and moon were lined up perfectly as that was certainly a fluke for this gas guzzeling GMC.

And GMC - Personally, I hate your active fuel management. I wish we could turn it off. I think that would help with the mileage (yeah.....I know what you'll say about that) and it would lesson the drive train noise that has been deemed 'Normal'.

 

[txe11]

I have a 2011 5.3 none 4x4 with 26,000 miles and am getting 12.4 to 13.8 mpg. What would cause this??

 

[D.A.E.A]

I found out you can put the tranny in manual and bump it up to 5 and it turns off the afm. So far, we are getting better mileage and ZERO driveline noise.

Will discuss with dealer this week. Maybe a tranny firmware update??