Can I *safely* run a Direzza ZII and Direzza ZII Star Spec tire on the same axle?

Question

Driving an '04 RX-8 that picked up a nail in the sidewall recently. I have 3 remaining Direzza ZII 225/45R18 tires with ~6/32 of tread left (started with 9/32). All I can find to buy are the ZII Star Specs now, which are apparently identical except made from a different compound that has improved performance. Would prefer to only replace one tire if possible.

Is it unsafe or going to lead to some other problem mixing these tires? I can move the mixed pair to either axle if there's some reason to avoid doing it front or back in particular.

Only thing I've been able to come up with is that one tire might lose traction before the other leading to some type of unexpected loss of control, but the grip on these is so high already that I've never managed to skid or break traction in normal driving.

Answer 1

You're probably ok. However, it would be far more recommendable to replace all four tires, especially since your other three are already down to 6/32. At 4/32, you should really replace them anyhow, so you're just delaying an expense for a little while at the expense of potential complications.

Because the material is newer and different, the risk is that you have less grip on one tire than the other, resulting in a risk of coasting, especially when the roads are wet or slippery.

At the very least, I would recommend purchasing two tires and putting them on the same axle.