Ive had my S for about 5 minutes so its time for new tires. The massive amount of torque is truly annoying so I was thinking of going with a slightly taller tire. 245/50/16s are 4% taller. When I tried to order these from Tirerack the salesman said they didnt recommend going with a tire that was more than 3% different than stock.

Does going with a taller tire truly affect anything besides the speedometer?

Also, there is a much larger selection of tires in the 245/50/16s.

 

'Massive amount of torque"??

The taller sidewall will squirm more and make handling less confident (same reason 17" and 18" wheels can improve handling). Your rear end will be higher than normal, but you would likely be the only one to notice. If you ever get a rear flat, your front and rear tires won't be close in size so you risk differential damage.

On the other hand, your highway mileage and rpm will improve, but almost too little to notice.

 

Your ABS may not work. Do not try anything taller than OEM at more than 2%.

 

If you also increase the OD of your front tires to the same as the rear, only your FD, acceleration, and gas mileage will be affected. But, like aggie mentioned, if you run the stock donut or other stock-sized wheel in the rear w/ the larger OD tire on the other side rear, the diff won't likey.