Advice on M5 all seasons
 

I need advice on tire sizing for all seasons on an M5. I don't want to get into a debate on summer vs AS vs winter but just want to know how much I can get away with on sizes.

The Toyo Proxes 4 plus comes closest but I need to go with a 255 or 275 vs the factory 265. There is about a 0.7 inch different in width between the 265 and others.

First, is this difference an issue? Second, would you go up or down in size. appreciate your feedback.