tesla440

I agree with Shorts. In my '05, I've had a couple of tanks at 23mpg. All freeway two consective tanks in a row. I've done consistant at 20mpg+ if I drive all freeway empty or small load. I have not been ever able to do that 23mpg since.

But I don't drive all freeway. Mostly city/out lying city areas. I get an average of about 16-18mpgs in that type of driving depending on load in the back.

AH64ID

Your 07 G56 has 3.73's, it was the only option with a G56 until 08 when 3.42's were released. 4.10's have never been offered with the G56.

White Ghost

i average 17 to 18 mpg unloaded and when loaded i get 10 to 15 mpg . the later is depending on wieght and wind drag.i should know because i use my truck for hotshot.i have never got more than 18 mpg.

rkelso98

A friend has a question that I thought I would bring up. He saw a decrease in MPG switching from dino to synthetic oil. All conditions the same from what he says. Anyone ever heard of that? He was getting ~18 with dino and now only getting ~15 with the synthetic.

Kilroy

Anyone ever notice a difference between diesel brands?

AH64ID

I haven't.. But I did get a bad tank back in January. netted me 13.5, where I should have been about 16.5. It was all fwy, wind wasn't a factor and the truck seemed to be working harder than it should. As soon as I filled up the mpgs went back to normal for the conditions, 16.9.