i got stock dana35 with prob 3.55 gears, jeepy came with a hitch but idk if i got the 3.73, im upgrading tires from 29s to 31 m/ts, and was wondering how much throttle response/mpg i would lose. also adding a tranny cooler

 

I am running 31's with the 8.25 and 3.55 gears , only marginal power mpg loss. Still works pretty good

 

i lost about 6mpg right off the bat, and then did a few upgrades to get most of it back. right now i'm about 2-3mpg less than stock.

 

shop rig has 31's and its right around 2 to 3 mpg difference for xj

 

dang 6 mpg?! that sucks haha, well i got the CAI and glasspack, also took my hitch and roofrack off and running no doors(4door) so i figure thats less weight for better mileage :P

 

you'll probably get better mpg with doors on.

 

so you wont be putting them back on when the warmer months are over?

 

oh i will be, i did the removal hinge thing for both front and back, but im shipping out to bootcamp(marines, mcrd san diego) in december so im not too worried. idk about mpg but i have noticed much better throttle response without doors haha