Pcleaners2
TJ Enthusiast
Mine can hardly go uphill still on the highway. Always downshifting. Replaced cats and no codes. Gonna try 02 sensors now. Hopefully this works. 4.88 33sI'd only consider 4.88 for 33's if your Jeep seldom sees the highway. Even offroad 4.56 is more than enough for 33's considering most offroading is done with the transfer case in 4Lo. Only if you think you may eventually go to 35" tires would I go 4.88 with your 5-speed manual transmission and 4.0L engine.
Ron your 4-speed automatic changes the usual recommendation for an axle ratio, due to its exceptionally steep .69 Overdrive ratio. At a MINIMUM for your 33" tires you need 4.88 but personally I'd go 5.13. Yes 4.56 is perfect for 33's with a 5-speed manual but don't pay any attention to recommendations made for those with manual transmissions.
My TJ has the same 4-speed automatic with 35" tires and its previous owner cluelessly only regeared it to 4.88 and it was constantly lugging on the highway, I had to keep turning the overdrive off. I regeared last year to 5.38 which really helped a lot, my mpg even went from <12 mpg to >14 mpg.
Bottom line is for your 33's I'd definitely go 5.13 if it was my TJ.
Any more input from anyone would be great