oh and 215/50-16 is an odd size, not to many choices in tires for that size... Some other members have recommended to me 225/50, and 205/55-16, a lot more choices in those sizes. 225/50-16 is only off by +0.7%, 205/55-16 is only off by +0.8% so either would be a good choice
The 215/45-17 is only off by -0.3% so there are some good sizes for you if you don't want to throw off your speedo by much...