A slight difference in rolling diameter doesn't matter. Car makers make their choices of tires for many reasons. I make my choices for similar but not identical reasons. I may want more grip or a softer ride at the expense of efficiency and price. Also, OEM tires are ripoffs.It amazes me that so many drivers think they can somehow decide on a better tire size than the car manufacturer. So many calculations are involved in determining the optimal tire size and tread pattern yet someone with no tire design expertise or it seems even basic knowledge of physics decides to go with a tire size that frankly under certain road conditions will endanger themselves and others. In many countries if an altered tire size is deemed to be a contributing factor to an accident the penalties for said driver can be severe. By all means play around with any aspect of your car, but unless you design tires for a living then be an adult and leave tire sizing to people who know what they are doing!.