Tire diameter question

[Entrepreneurs In Cars]

Question for the tire geeks in the group. I'm working on a sponsor for next year on my channel, and need to pick tire sizes for the M5.

Currently I have Michelin PSS with a 275/30/20 on the front wheel, Michelin says the tire diameter is 26.5" the only tire size available to me for fronts from this potential sponsor is a 285/35/20 so the diameter would increase to 27.7".

Aside from filling the wheel gap a bit more, any tire experts here see any issues with going to a tire that's going to roll over an inch taller?

It's been suggested that BMW may void the CPO warranty over something like this...

M5 is on factory suspension, and rolling on dinan 20's that are .5" wider than stock.

[13M5F10]

Originally Posted by Entrepreneurs In Cars

Question for the tire geeks in the group. I'm working on a sponsor for next year on my channel, and need to pick tire sizes for the M5.

Currently I have Michelin PSS with a 275/30/20 on the front wheel, Michelin says the tire diameter is 26.5" the only tire size available to me for fronts from this potential sponsor is a 285/35/20 so the diameter would increase to 27.7".

Aside from filling the wheel gap a bit more, any tire experts here see any issues with going to a tire that's going to roll over an inch taller?

It's been suggested that BMW may void the CPO warranty over something like this...

M5 is on factory suspension, and rolling on dinan 20's that are .5" wider than stock.

What size tire are you running on the rears? I don't think 285 will be an issue, however, you'll want to have very little difference from front to rear in regards to diameter.


Check out a tire calculator online and input the front and rear measurements.