Im thinking you should do what you want. If you would even consider selling your truck then maybe you should? The next owner will probably be on here within weeks. Just do what you feel is right for you.

 

my 94Z28 6-speed was a lot of fun but i'd never go back to an F-body. 28mpg with intake and exhaust was easy if all highway & 3.42 gears. i'm sure the LS1 motor was just as efficient or better. i went to 4.10s and quit driving it every day which meant it was "play" car and usually got 17 mpg... with 3.42s I probably averaged 22mpg city/hwy and not driving it too hard.

i concur with not trading a vehicle solely b/c of gas mileage. it all comes down to which one you really want to own and drive.

 

Wow, I'd move. lol...

 

My '98 6spd Z/28 got around 27 mpg on the highway. The 6th gear is real tall, so it would only be pulling about 1500 RPMs at 70 MPH. But I didn't have enough restraint to baby it the rest of the time, so I doubt if I ever averaged any better than 16 or 17 mpg.