I only saw one reference to this in a search, so here goes:
Can the MINI computer be reprogrammed to account for different tire sizes? I am currently running stock 195/55-16 RFs and would like to switch to 15s. Tire size calculator says 235/50-15 is closest to stock diameter ( <1% var.) but 235 is getting up there in width. I want to keep speedo/odometer error to an absolute minimum. (mostly odo, as smaller tires rack up the miles quicker)
Has anyone had a dealer do a reprogram?

 

Guess not.

 

best bet to close-to-stock on the 15" is either 205/55-15 or 225/50-15

both will be about a -2.3% diffence, but conside the stock 15" cooper tire is 175/65-15 wich is -2.0% diffence to the 16" standard tire.

SO.. compare the Stock MINI 15" to these options and you're only off bt 0.3%.. confused enough?

Basically, it's within the margin of error and nothing to worry about.