I've had both engines, the 4cyl was a little bit better but not enough to make it a deciding factor. These vehicles are not fuel efficient for sure! That being said, I was getting 12 MPG in my F150 and I'm doing around 14 or 15 in the Jeep with the 4.0 and 33's
-2013 JKU Sport, bone stock, Auto with 3.73's
-1998 ZJ Laredo, 4.0 42RE Selec-Track, 30" M/T tires
I average 17 MPG with a healthy 2.5 my buddies with 4.0 average 15 This is for mixed city/highway with occasional light trails in the summer and hell snow up to your butt in the winter. I've gone as high as 20 MPG with only highway driving, but city driving just absolutely kills the MPG's. I might as well be driving a bus in the city, that's how bad it kills it. I'm running the stock 4.10 gears with 31x10.5 tires.
But really I hope you have a *lot* of money for gas because no matter what a Jeep is going to eat it
Last edited by oldtime_ironman; 08-20-2011 at 07:07 AM..
Reason: relevant details
i've had both, and both got about the same fuel economy for me. i read somewhere on here about how the increased power of the 4.0 offsets the decreased fuel consumption of the 2.5, so it ends up being a wash. so if it's a decision between the two, i'd recommend going the 4.0 route. after struggling behind the 2.5, i feel like i can tow the world with it