fuel mileage

[fresnodog]

Just drove my 2008 sierra 4.8 four speed from Fresno ca to primm nevada took a whole tank i only got 13.5 mpg drove 75 mph on the way up here i cant believe the horrible gas mileage i usually averaged above 19!! Anyone else have that problem?

 

[Z15]

The faster you drive the more fuel you will use.. Also, were you using E85 fuel? Lots of complaining about mileage in some parts of the country and its suspected its due to increased Ethanol content in the fuel. The more the ethanol, the lower the mileage because Ethanol has less energy in it.

This could be just an isolated event for that reason...

I just this week made a 500 mile round trip over to Duluth, MN with a 2010 Sierra E. Cab SLT Z71 All Terrain, 5.3L and loaded. I got 17.7 mpg and about 100 of those miles I drove in AUTO 4x4 due to snow and ice covered roads.

 

[gantt]

i made a 600 mile round trip from middle georgia to the blue ridge mountains. had around 1,000 pounds in the bed. (motorcycle and luggage) . I have a 4.3L with 3.23 gears(they suck) and a single cab standard bed. In town alot and i averaged 17.3 m.p.g. I normally get around 14 in town at home. The key is to let the truck slow down up hill. dont fight to keep the same speed, it doesnt hurt to loose one or three mph. much faster than 55 mph and your mileage can decrease. Also, a coat of wax will help. haha, just kidding. I wish it would help!!