Just towed my 2,200lb trailer with a Z06 yesterday 95% freeway miles, mostly in the 60-65mph range and got 9.5mpg.

Anyways, so what gears does GT5 represent? 4.10's?

As for the larger tires on the freeway giving better mileage... that is what some people think and would probably be true if it were not for the large weight difference.

2,000rpm, hah. I'm usually at 3,000-3,200 rpm.

The truck is mostly stock with a drop in K&N filter (less then 10,000 miles on it) and a Flowmaster catback (dual 3" pipes into one muffler, single 3.5" pipe/tip coming out.

It does have a basic tune, but never been on the dyno. Maybe I'll have my local guy tune it for me, with mpg as the main objective...

 

I also want to put in electric fans... I don't think that will gain me any MPG on the freeway, but maybe around town.

 

LOL, just saw this post.

I wish your damn truck wasnt 8-lug so you could just slap my Chevy wheels on therer and try it out.

 

Dude I feel shitty about not getting that info, just checked the glove box and I got "GT5" so they gotta be 4.10's

 

I just noticed this thread as well. If you're looking for better gas mileage and don't do a lot of off-roading, look into some all terrains in 285/75 if you want to keep that size. A less aggressive tread pattern will net a little better mileage than mud tires like your MTR's. From what I've heard though, about 12 mpg is about as good as it gets on a 2500 four wheel drive with a 6.0.

 

what kind of mileage could i expect from a ecsb z71 5.3 leveled with 305/70r16 on classic IIs with stock 373s

 

prolly a little worse than stock, most times big tires dont help unless you got a big gears, (4.10's) and your gonna loose some low end power too.