Because there was still some question about what tires could fit on the FiST, and because I have limited funding, I made the decision to buy a pair of the 225/50 Rivals and 225/45 Dunlop Z2. I liked the idea of getting a few extra mph at the top of second with the Rivals, but was worried that they wouldn't fit. Even though the Rivals rub near full lock, they should work just fine. If I had known for sure that the Rivals would fit on all four corners, I would have just ordered a full set. I don't think that running different tires is ideal, but I want to make the best of the situation. The performance of both tires should be similar enough that I don't think that the difference between the two makes will lead to any adverse handling conditions. Now I have an opportunity to effectively run two different tire setups just from swapping front to rear. The differences in tires are/ may be: the gearing responsiveness/ transition behavior heat tolerance performance in the rain (fingers crossed this doesn't matter all season) Even though they are both 225s, the Rivals clearly have a wider contact patch. The Rivals also give me about 2.5mph extra at the top of second gear. Does anybody have any thoughts on what I could do to optimize this situation? Is there anything I'm not thinking about? My club doesn't have a test and tune this season, and there are no close events in other clubs before our season opener. That means that I will be doing this by trial and error at points events. Any advice is welcome. Thanks all.