TB gas economie

My TB 2003 L6 LTZ "eats" gas as fast as 8 mpg. The manual tell about normally will be 16 mpg. I went 2 times to the automotive services without results. Is there any one with the same problem?

wow..Mine is not that bad. I get about 17 around town and 21 on the highway.

WOW! I have the V8 & I normally get (worst) 10mpg, when I am flogging it! To my normal of 14.5mpg which is in all stop & go.
Highway, I have only been able to get around 17.2, but that is also with speed variations of 65mph to around 75-80mph.


Double check your air cleaner to make sure it isn't dirty or that something is obstructing it. That would really hurt the mileage there.

Otherwise, do you have your foot in it on a regular basis?

I read in another forum about a problem with cracked aluminum piston heads. The guy with the problem said his truck was getting 7mpg. GM has extended warranty to address the issue, 100,000 mile, but is relucatant to do the work until engine fails. Maybe this condition is causing your poor mileage too.

My '04 with the i6 and 4500 miles just got 21mpg on a run at 63mph.