Home Forums Gear Hunting Trucks and Four-Wheel Drives chevy silverado 4x4 "auto" or "2 hi"

My 99 Silverado Z71 had a new transfer case at about 150K miles. I used the auto feature all the time (winter in AK) I knew It was going because I could hear the chain slapping the case.

On the other hand, my wife's 03 Trailblazer has the same feature. It stays in auto all winter, currently has about 140K miles on it and the transfer case is as tight as it ever was.

I have an 04 Chev 1500 Z71 with 265000 miles and just replaced the transmission for the first time. Usually run in 2 hi except when road conditions are variable and then in auto mode. Mileage is about 18-19 overall with not much observed difference except when I go to 4Hi which drops mileage significantly .

I have the 5.3 L Fle Fuel engine on my 2011 Z71 Silverado and I get nowhere near that kind of mileage, especially in winter!

Aroound town and short highway i would say I average 15 to 15.4 mpg.

I had an 05 z71 crew 5.3L non FFV and only got 15-16 or so in mixed driving.