Well, I got a heck of a deal. One of the girls I work with, wanted to get new tires on her truck. She didn't have the time to take it to the shop, so she asked if I would take it for her. I thought sure, no problem. Well...to make a long story short, she gave me her old tires (BF Goodrich Long Trail Radials (265/70R/16) for taking her truck. Only had 6000 miles on them. I was running 245/70's. So...will this knock my speedo off at all?