I have a 2007 unlimited x which came with 16 in .A friend has a sahara which came with 18 in rims with 255/70r/18 .He replaced them with after market set,can I put his old 18 s on mine.If so will it effect the speedometor.thanks

 

as mentioned, yes, they will fit and depending on what your tire size is now, your speedo may be slightly off as well but, just slightly. question is, do you really want to install a set of 18" wheels? personally, i wouldn't as it is an odd size and one that'll make your future tire selection smaller and more expensive.

 

thanks my current tire size is 245/75r/16 if it is only off a little i can live with that .I check the speed with my gps today and the speedo is a little under that on the 16 in .As long as the 18 go on all is good .

 

You should still get it set correctly, not only is speed off but your odometer will be off too which is illegal. Also messes with your gas mileage stats.

 

totally agree here, I regret staying with 18's and now I am buying new wheels with my new tires. Like everyone has said, your speedo will be off slightly but I wouldnt worry until you go bigger then I would get a procal or superchips etc. to calibrate the speedo.