just bought a slightly used 2005 Mini coupe with stock ContiTouring Contact tires 175/64R15 on it. Front tires were worn out at 24,000 miles and have to be replaced so after looking at a lot of tire rack reviews that were negative on the Conti I am looking for another tire recommendation. After reading a bunch of posts on this site i am thinking I should put Kumho Ecsta ASX tires on the car. Now i am debating tire size between the 205/50 vs 205/55. Any info on benefits of either size? Like the lower profile of the 205/50's but wonder if ride quality will diminish significantly. Car will be driven in a spirited manner by me but also will be used by my 16 yr old son and my wife so i need to straddle the fence between handling and ride quality.

 

For street use, it's recommended that diameter of plus sized tires be within ±3% of the factory specification in order to maintain accurate speed data going into the computer, thus keeping odometer and speedometer changes negligible:

205/50-15 = -3.7%
205/55-15 = -0.3%
195/60-15 = +1.1%

205/50-15 would be OK for the track but 205/55-15 or 195/60-15 would be best for the street.