mred

iTrader: (5)

when you swapped out your old motor and put in a 6.0,what was your mpg.
i have a complete lq4 and i am anticipating the swap.
due to the fact that the mpg would not be any better than the 5.7 currently in my 1997 swb.
i have heard stories of guys doing the swap in the camaros and the are getting 20+ mpg. i dont know how true this is,but anyways.
Ed

76LQ9TA

iTrader: (1)

MPG depends on what vehicle the engine is in. I am getting 11.4 in my 2006 2500HD over 22,000 miles and between 15 and 20 in my 81 trans am w/ LQ9 and 4L80E. On a 250 mile trip just on the interstate it made 22 mpg.

G-Body

iTrader: (4)

I was getting 13-15 city with the 305 in my el camino. about the same with the 5.3L and when I swapped to the 6.0 it went up to 14-16 in the city. Always been around 16-20 on the highway. But keep in mind I do have a 3.73 gear, and short 26" tires, oh and I might drive it a bit hard........I ripped the brackets off the front of the seat for the second time a couple days ago. oops.

the_merv

iTrader: (88)

With my 402 LQ4 Stroker I could get 24-26 on the highway.. then again that a T56 car with 3.50's in the back.. I do 85mph at about 2K.

52 Rat

iTrader: (4)

My '06 HD with LQ9 gets around 13-14. My friend has a '08 Z06 and he gets around 26-27 on the highway. As stated above, it depends on the trans., rear gear, etc.

kirtondog23

My truck with 38inch tires get s about 14 or so average but hwne the tires were at max inflation and I drove carefuly I did get an average of 17 or so.

mred

iTrader: (5)

your application will probably be the closest to my truck,so 15mpg is what i figured it would get if i do the swap.
i will not do any cam swap or anything,i want to try and get 200,000 miles out of this motor which should be very doable.

G-Body

iTrader: (4)

Mine is getting a cam as soon as I get the time to install it. The hot cam is sitting on my floor right now. I figure I will actually pick up some fuel economy with the hot cam. The cam should give me better breathing in the mid rpm from 2k up and at 55mph I am at 2000 rpm......so my normal highway speed usually puts me at 2500-3000rpm cruise speed, and the cam should give me more torque in that range. I picked the hot cam because it was cheap, wasn`t too big, and only has .525 valve lift, so while it may give up a couple HP to cams that have high ramp rates, it will be very easy on the springs and should be able to run forever with LS6 springs.

You will probably get better than 15, my driving style is pretty harsh. The last time I went to the track I put on 130 miles on the tank of gas, most of that was highway....and I put on 41 passes (yep thats just over 10 miles at WOT ) and I got 13mpg for that trip.