Re: 93 jeep wrangler
does your jeep have the stock dana 35 rear axle(c-clips...tiny axles...weak housing...just plain bad)?
have the gears been changed and what are they?
how wide are your rims? because 15x10s stick out a bit further than 15x8s giving the tire a lot more leverage on the axle.
there are a lot of variables, but...
you could safely run 33" tires as long as you are easy on the throttle when off road. your acceleration will **** more than it does with 31"s. top speed would theoretically be higher but your 4cyl will prolly never get you there. changing from 30"s to 33"s on a jeep with 3.73s and a 5 speed transmision will make 5th gear completely useless. changing your gears(depending on what they are now) to around 4.10:1s will help the acceleration a lot. do not go any lower(higher numerically) than that because the pinion gear is way too small even with 4.10s to give the owner much confidence. there are complete dana 35 upgrades available that come with ring and pinion, locker, stronger axles, and a housing truss that keep up with 33" tires fine, but, they are very expensive. plus you'll have to do the front axle to match.
performance upgrades like a header with a free flowing exhast and k&n air filter may help some too.
--My truck: 2006 GMC 1500 crew cab, Kenwood DNX570HD, DLS front stage, JL JX1000.1, JL dual 8w3v3 microsub enclosure, Second Skin deadening.
--Wife's car: 2013 Chevrolet Impala LTZ, Kenwood DNX470, GermanMAESTRO components on CT125.2, 2x AT10"s on an AT800.1, RF Deadskin deadening.
--Work truck: 2014 GMC 2500 crew cab, Kenwood DNX470, Kenwood front stage, DD M1A on a pair of American Bass XD10s.