Expected Tire Wear, but not like this?

[JT1]

I thought I was being slick/lucky, heading into winter with my Cup 2s with 6K miles and 2 track events just about worn out. I wouldn't need to worry about them getting cold this winter since I'd replace them in the spring.

Took the car to a cars and coffee on Saturday, just about to pull in and get a low tire pressure warning, right front. Obviously a lot of car guys there so we try to figure out what I ran over, and if I could plug it to drive home, again worn out cups 2s.

I get a floor jack, take of the front wheel, and wow some weird wear. What is the inside edge of a cup 2 supposed to look like? Mine look like something was rubbing the last 1/2 of width, tire is just missing there, like a 45° chamfer. Looks like it was rubbing on something. Look around in the wheel well, all looks good, like nothing was rubbing. I do have Vorshlag C&C plates and a track alignment, but it looks like the entire car had been driving on the innermost 1/2" of tire.

Has anyone noticed wear like this before?

Did try to plug where it had worn through, but the rubber was too thin around it, it did hold about 10 psi, but I called for the flatbed. The 10 psi was enough to roll it on and off the flatbed and in the garage after it got off the truck.

Hard to capture in pictures how the inside edge is missing.

View attachment 897058

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[sk47]

with 6K miles and 2 track events

Hello; I have read posts of similar tire wear. I do not know if your tires are square or staggered. If square a rotation every couple thousand miles. Maybe run more air pressure. Maybe investigate what sort of alignment promotes tire life. Maybe having a set of wheels/tires for track and a harder set for road driving.
Will boil down to your goals and pocketbook.

Good luck

 

[mustang88_cars]

I think most owners have gone to a tire like a Michelin 4s or a Continental Extreme Contact and had their alignments set to GT settings due to the exact problems you’re having. Obviously this solution isn’t track ideal. I’m interested to see what others have to say in this topic. I have a set of Cup 2’s on my car that have 500 miles on them so I’m interested in solutions to this myself when I get to the point of changing these tires.

 

[skinnyb]

Classic S550 thing. All Mustangs do it to some extent. Ususally due to excess toe. A really good alignment shop can make it better, but it will happen again on the "track" alignment. I had my Mach 1 with Cup's re aligned and PS4S and 12K miles so far so good..

 

[NMoore]

Classic S550 thing. All Mustangs do it to some extent. Ususally due to excess toe. A really good alignment shop can make it better, but it will happen again on the "track" alignment. I had my Mach 1 with Cup's re aligned and PS4S and 12K miles so far so good..

Correct. Excessive wear on the inside edge of the tire is the result of aggressive toe out. A bunch of negative camber doesn’t help but it’s primarily toe.

 

[JT1]

My alignment says total toe is -0.10°. Is that aggressive toe out?

Camber is -3°

 

[Evolvd]

Put the toe as close to zero as you can get it for street driving. Having -3 camber only makes it worse.

 

[skinnyb]

6000 miles is a LOT for Cups, especially with track time. Mine had 4400 miles and they were SHOT, upgraded to PS4S and haven't looked back. They have a lot more tread to work with so naturally will last longer. I would get the toe as close to zero as humanly possible. And get that camber down some if possible. Unless you plan to track regularly, then just pay to play I guess

 

[GrabberBargeCaptain]

My alignment says total toe is -0.10°. Is that aggressive toe out?

Camber is -3°

did all the tires do it?

 

[JT1]

did all the tires do it?

Both fronts, haven't got the backs off yet.

 

[DopamineQuest]

My inner edges were cupped to SHIT after 15k miles (PS4S). Got an alignment and went toe 0 and camber only -1.5, hopefully this set does better.

 

[GrabberBargeCaptain]

Michelins, at least their summer tires, tend to wear more in the inside of the tire i've noticed, due to a type of rubber they use there (it's not all one type of rubber/material used on the tire). Yours is pretty bad though and like others have said, toe-out/negative toe will exacerbate it. It will make your car feel twitchier and more responsive off center though, so some people like that.

 

[saleen367]

That's definitely a toe out + negative camber issue. I always move my alignment (camber) back to a street friendly setting after a track day. In fact I do it at the track before leaving. Zero toe isn't the optimal toe setting on track, but it is for tire wear, and with Cup2's at $2900/set its zero toe and -1.2 camber for the win on the street.

 

[Skye]

Glad you caught it before damage or accident.

Someone in the 7G forum recently had a similar experience.

I measure tread depth a few times a year.

Previously, I was using a traditional pen-type meter to check my tread wear. While it worked OK, it left me looking for something more precise. I purchased the Intercomp gauge from Summit. The device provides for sub-mm resolution. It's got a nice weight to it. The movement of the needle suggests a roller bearing inside.

https://www.summitracing.com/parts/...6dLp0ErfkpTnMpqiXoh8e52-kEUWv4EWDx_9BbcNI3GeV

I also use an Autometer 2160 for pressures.

https://www.summitracing.com/parts/...4QclorS1k0Rfv9O6P9G0lE0OfO1if1ea04xF-kvIkZwMf

 

[agmattocks]

Yes i have the same problem on my Mach 1 HP. Set to track specs kills the tire on the front passenger side (-2). I've had the fronts set now to (-1) by modifying the strut. The rears are still at track spec but i have a kit to adjust that which i will put on as soon as the mosquitoes are gone lol.
I use Nitto Invos they last twice as long as the Cup2s with similar grip levels. Attached is what mine looked like. Now i could have kept the drivers side for a spare (I should have).

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