Yeah, initially 215/45/17 & 225/45/17 were mostly available US side, but since around year i noticed PSS-es of those sizes also listed in local internet tire shops here in LV (from which i guess, they should be available elsewhere in EU too).

Hmm you may have a point here. I live in Michigan and the FRS I bought came with the Bridgestone Turanzas which are All-seasons. This means that the 2013 Model came with 3 different tire selections leading credibility to your statement as well as @Tcoat about the design team selecting optimal tires rather then being swayed by contracts.

This...exactly

Yes. As I clearly said the specs are the primary importance. Price comes way down the list. They determine what they want on the car and THEN look for the best price in that range. It is more likely that Bridgetone met the AS specs they wanted better than anything that Michelin had than that they were on sale at the Joes Tire Wholesale Warehouse that week.

This^

So, I'm actually an engineer for a tire company, and this is not how it works. When an OEM seeks out a tire, they reach out to the tire operations that they feel can provide what they want. Engineers from the OEM give specific characteristics of the vehicle to the tire engineers and the team goes through several "iterations" of test tires until the OEM is happy with how the tire performs on the car. That tire is specifically tailored to the vehicle it goes on. The price is only one small step in tire selection.

That being said, to the OP, 225 45 is a good match on this car for a more grip oriented tire from the performance summer category. I upgraded to an high performance summer tire in the stock 215 size and I'm not lacking any grip on the street and still have tons of fun at autocross.

Makes sense that way. Still price and winning contracts play a role. Always learn something from the forums. Cool beans.

why all season? Do you really see that many cold/snowy/icy days? Honestly if you do getting winter tires on the stock wheels and a lighter better wheel with summer tires would be a better option. This car on good winter tires is totally rock solid no matter how much snow you see.