I’m looking for thoughts on tire wear. I’m running oem pirelli p zeros. Starting with 100% new tires, I put about 2k miles on the tires, including 2 track events. Pictures below are rear tires after approximately eight 20 minute sessions at North Carolina Center for Automotive Research (NCCAR) and eight 30 minute sessions at Carolina Motorsports Park (CMP). I was told both tracks are hard on tires.
Passenger side tire:
Drivers side tire:
The tires wore differently. It’s hard to see unless you expand the pictures.
Passenger side looks “normal” for hard track use, I think. But, still not down to the wear bars. More or less even wear across tread.
Drivers side...the middle of the tread is worn to the wear bars. But, the outer tread isn’t. Normally, I’d think it’s due to running air pressure too high.
However, I intentionally ran 30 psi cold, which is 2 lower than Ford specifies. Hot, on track, the car showed 34 psi in both rear tires. (I ran the pressure low because my original tires both wore out in the middle, even though I kept the cold pressure at 32 psi cold. My tire shop said the only explanation was that I ran pressure too high, which was obviously wrong.)
My son suggested that another possibility is the oem wheels - 9.5” wide - might be too narrow, which would squeeze the 275 width tire and cause the middle to wear. But, that should affect both rear tires the same and both tires wore differently.
I’m concerned about two things:
1. Hate the thought of having to buy new tires every couple of track events. (I realize the first thing to help is get a square setup so I can rotate tires.)
2. Uneven wear that I don’t understand.
Thoughts?
Thanks,
Shea
Passenger side tire:
Drivers side tire:
The tires wore differently. It’s hard to see unless you expand the pictures.
Passenger side looks “normal” for hard track use, I think. But, still not down to the wear bars. More or less even wear across tread.
Drivers side...the middle of the tread is worn to the wear bars. But, the outer tread isn’t. Normally, I’d think it’s due to running air pressure too high.
However, I intentionally ran 30 psi cold, which is 2 lower than Ford specifies. Hot, on track, the car showed 34 psi in both rear tires. (I ran the pressure low because my original tires both wore out in the middle, even though I kept the cold pressure at 32 psi cold. My tire shop said the only explanation was that I ran pressure too high, which was obviously wrong.)
My son suggested that another possibility is the oem wheels - 9.5” wide - might be too narrow, which would squeeze the 275 width tire and cause the middle to wear. But, that should affect both rear tires the same and both tires wore differently.
I’m concerned about two things:
1. Hate the thought of having to buy new tires every couple of track events. (I realize the first thing to help is get a square setup so I can rotate tires.)
2. Uneven wear that I don’t understand.
Thoughts?
Thanks,
Shea