The 4 cylinder models won't compare to a newer XJ, mainly because of power. I know because I own an 86 2.5 liter 4 banger, TBI, not a bad Jeep. It performs well offroad, but gearing is going to be an issue, then once you change the gearing your mileage is screwed. The TBI is also "Cold Hearted" mines a b*tch to start in the winter, its like a carburated engine. If I didn't get such a good deal I would have bought a 4.0 liter but who can beat 35 bucks. There are plenty of deals out there, just look around. But check for major issues. Last year we rebuilt the old tired 4 banger, its a stought little motor, not much for bogging down, but reliable. This Christmas break my bro and I replaced the worn bushings with new polyurathane and put a simpe 3 inch lift under it, welded gussets into the top and lower control arms, helped stiffen the suspension. The suspension on all the XJs are bacically the same. Its the drive train thats going to vary, nothing really beats the 4.0, the 2.8 or my 2.5. My main point, go newer, avoid 4 cylinder models, but you can make them work for you, if you want.