Just bought our first jeep in August. 2011 Rubicon Unlimited with factory 4" Mopar lift and 35" BFG KM2's on Mickey Thompson classics (non-beadlock type). Just bought bushwacker flat fenders, installed rears Sunday and plan to install fronts next Sunday. We can see now with the fenders that 37's would be the ideal match for the Rubi at least visually.
We took a roadtrip prior to the lift and tires and felt the highway performance was very good considering some of the negative things we had read. We traveled 80 mph no problem with gearing and power very smooth. After the lift, wheels and tires came in we installed an Airaid cai and a Banks catback then took another roadtrip and the highway performance was horrible; no power, lost overdrive. Initial offroad performance seems fine with improvement in low end power due to intake and exhaust upgrades.
Now for a few questions;
1. For 35's which gear ratio would be recommended for best overall performance. We don't want to sacrifice offroad performance but we also want to be able to drive on the highway loaded up with all our gear and still be able to travel at 75mph @ 2600rpm's (is this realistic).
2. That said, we would also like to consider the 37's now but wonder if there are too many consequences and upgrades required to run them. Are you able to use the stock axles without beefing them up other than changing gear ratio, and will the 4" lift be able to handle them. What other problems might we run into.
3. Do we need a performance chip and if so which models.
Any and all of your comments/recommendations will be greatly appreciated.