just bought a used 2006 crew cab with factory chevy 20" rims, The current tire size is 275 60 r20, my gas mileage sucks to say the least. The truck has a 5.3, 3.73 gears and a g80 what would be a better choice on tires to help with gas?

 

Damn; that's a 33" tire. Is it lifted or leveled, and do you plan on lowering it? I personally like 275/45's for 3.73 gears; 285/50's look better for mild lowering/leveling and are better suited to 4.10's.

Anything smaller and narrower will help you out to an extent; I'd go with one of the two I just suggested depending on how you want it to look.

 

I drive to truck to and from work and I work in a refinery so lots of bumps. I do like the 285/50 I was just checking if there were any better options to save on fuel.

 

well I went with a set of 275 45's in the Eagle gt 2's

 

good luck, 275/55 is the stock size fwiw, hope you plan on a drop with the 45s