I apologize in advance for any ignorance. I have a 4 cylinder, 2001 Jeep Wrangler 5 spd manual. It has about a 3in.-4in. lift and the tires specs are: 33 x 12.5 OR15L7 108 R M+S. My Jeep, currently, is very slow in acceleration. It seems to struggle at highway speeds and I don't push it past 60 mph. It is fine on residential roads but I think the bulky tires are slowing it down on the interstate/highway. I rarely take it off road (the previous owner did take it off road frequently), the treads are almost worn out, and I'm just looking for a good tire replacement that will get me better mpgs and something that will make my Jeep a little faster. I would like the same tire height, just skinnier, I guess. Also, would I have to buy new rims if I did get skinnier tires? I guess the rims would have to match specifications for new tires.I'm assuming that the axles will need to be re-geared as well. Any information would be really helpful. Thanks!