[MySport]

Could anyone let me know what tyre sizes are fitted to the 21” rims that come as part of the M Sport + pack?
I’m looking to order a M40 in the next couple of weeks, but runnng costs are a consideration as I do 25,000 miles a year. I have priced up the standard 20’s and they’re within budget, but I don’t want to lumber myself with onerous replacement costs if I go for 21’s.
I’m also curious to know if anyone has had experience with regards to their life expectancy.

Thanks.