I have an interest in upgrading to wider tires for summer, but am just fine with the Style 278 17 inch rims that are stock with my 2010 non-sport 528i. Not planning to lower or modify the suspension. What kind of success would I likely have with a set of 255/45 17s?

 

Do you not want to go with larger rims and add spacers for a wider stance instead? 18" or 19" with spacers would fill it up really nice. Just a thought.

 

AFAIK the recommended up-size is 245/45-17 ... so if you go wider let us know how it goes ... GL!

 

That's true - the 245s would be an exact diameter match, while the 255s would be about a 1.5% increase in diameter. That increase would go about halfway to offsetting the sizable BMW speedometer error, which would be a nice bonus.

 

You should bookmark this website - if you decide to consider other tire size options it will come in very handy http://www.miata.net/garage/tirecalc.html