I’m trying to decide which to buy and I’m really only interested in hearing from people who have tried both. It seems the people who have only used one or the other are pretty enthusiastic but they don’t necessarily know much about the other.

An actual experience as background. When my original tires wore out I wanted to replace them with the new MPSS but TireRack didn’t have them so I went with BSO-4s, which was a highly regarded tire. It was fine with no serious problems and I got 13 track days out of them.

When the BSO-4s wore out I replaced them with MPSSs. I was about 5% faster from the first day and eventually set a personal best that I have not matched since. I got 18 track days out of them. So, if I were comparing the BSO-4 to the MPSS I would clearly recommend the latter. Neither had any problems on track but the MPSS was quicker and lasted longer.

My driving has improved and as I’ve learned to trail brake I’ve found I can carry as much as 15mph into a medium speed turn. That’s good but the bad part is I’m limited to how much stock negative camber I can get and I’m beating the hell out of my MPS4S outside edges. That’s important. I can’t get the camber without spending a lot of money I don’t want to spend so I need pretty stiff sidewalls to compensate.

I know these tires don’t last long but I only got 13 days out of my PS4Ss before I corded the edges. If I can get anything similar with a wider contact patch I’ll be happy.

 

That should have been 15mph more.