...this have on my speedometer? I had to change the rear tires on my car. They were studded winter tires and although I had them balanced repeatedly, they vibrated at high speeds. I couldn't afford to buy new tires but I had a set of larger tires in my garage that were practically new. I installed them on the rear. They fit but did slightly raise the rear of the car about an inch. I'm trying to find out how much they throw off my speedometer so I can adjust my speeds to avoid speeding tickets.