You want to swap the drive axle, so rears for you. And there is a terminal point where bigfer tires will be more harm than help, but i don't think a reasonable person will encounter that. If you do 16s front, 17/18 in back, you will help lower engine rpm, and create a low pressure zone under rhe rear of the care- more downforce, in theory, but that, in theory, means more drag.
Edit:
From my limited time on the site, mcrews knows his stuff. His guides are pretty good, and you might want to go his and my route and buy a more aero efficient front fascia. Just an idea.
|