ok so im on 16 inch wheels right now..if i am going to upgrade to an 18 inch....does my computer need to be tweeked at all?

 

only if the overall tire size changes... stock tires height is 27 inches... you can get a 18 inch tire that's 27 inches so no need to change the tune..

 

do a search for a tire size calculator.....that should help you determine what size tire you should get or what chnges will have to be made in your tune to compensate for the bigger/smaller overall tire diameter. Good Luck