I am a bit confused on the benefits of changing from stock 14" tires to 15" tires: I have a 71 442 and a bunch of 14" rally rims for the car. What is, if any, the performance benefit of switching to 15" rims? Will the car handle better? I understand the physics if the tire (with rim) has a bigger diameter or circumference, on one revolution the tire will travel a greater distance than a tire with less a circumference? Is that the difference? or is there some handling benefit? and if so why didn't GM do this? I also understand that the smaller tire will be easier to spin.
Or maybe I am on the wrong track and by changing to bigger rims and tires it just fills out the wheel well more and looks better, nothing more?