Hi All. I have Michelin Pilot Super Sports
225/40/18 Front, one sidewall damaged
245/40/18 Rear, one sidewall damaged.

They were new last season, it pains me to throw them all away when two of them are in great shape. Mine have the "star" on them. I've looked around and I can find a single front and a single rear, both of these are also Michelin Pilot Super Sports in correct size but are missing the "star".

My question is, what does that really mean in terms of the tire and its construction, and can I mix those on the same axel as non-star tires?

This on my 2017 M240i xDrive.