GCM 2
New member
As far as mileage goes, yes an LS3, LS6, LS7 can see upwards of almost 30mpg hwy. I have owned quite a few Corvettes, all eventually ended up with more than the stock hp they originally came from the factory with (my stock 2008 with LS3 had 433hp, that's more than most need). Around town a conservatively driven corvette will see about 18-20mpg if you short shift pretty regularly thru the gears.......but you start leaving stop lights a little harder and the mileage drops quickly to around 12-15mpg city. My Z06 in the picture below had a bored and stroked LS6 that was Dyno'd with 630hp at the wheels, so well above 700hp at the motor and it was a daily driver. Around town it saw an average of about 13mpg, on the highway it saw 25-27mpg without trying. That's the beauty of computerized motors. But here are the two major differences between my corvettes and my JK if they were to run the exact same motor......2500+ lbs and beam axles. A Corvette is a lot lighter, and has an aerodynamically smooth top side and belly. The JK is a porker and has a square brick of a body and because most are lifted, everything hanging underneath is also now a wind break. That's where you would lose any chance at 20+mpg in a JK. Add 2500lbs to a corvette, lift it, put solid beam axles and you have the exact mileage a V8 upgraded JK will get. V8 upgrades are about torque and power, not about better mileage.
