Front tires slipping/grabbing - 986 Forum - The Community for Porsche Boxster & Cayman Owners

I now have a 2013 Boxster 981 with Pirelli Pzero tires on 20” wheels 27k miles. When turning sharp at low speed it seems the front tires are slipping and grabbing as if they aren’t tracking the same exact angle. This also happens in reverse.. typically when I pull in and out of the garage. I am running 32 PSI pressures. Anyone else experience this?

I don't have experience with this on a Boxster, but my C7 Corvette does this. It can be common cars with summer tires.

Was there any suspension work done on your vehicle recently? I have only experienced this once and the vehicle needed a proper alignment to get the issue sorted.

No suspension work. This car has a clean history at 27k miles. I was wondering if it’s the tires, the psi, or normal for the 20” wheels.

Does this only happens when you have the wheel hard over? This is fairly common with large tires on RWD vehicles under that circumstance - the front tires are turning in a radius that is shorter than the rear axle can accommodate, so the rear essentially pushes the front tires forward instead of them following the full curve. Does that make sense? For good measure I would have the alignment checked to make sure that all is well. And ask them to show you the measurements - just because they fall in factory specs doesn't mean that all is well, especially if right and left are not identical. If that checks out though, check your wheel wells to make sure there are no signs of rubbing. If not then I wouldn't worry about it. Sent from my POCOPHONE F1 using Tapatalk

Hard over yes.

Good points made by ike84. On my 986, I actually had the dealership calibrate the sides and was surprised to learn one dealer could get it all within factory specs whilst the other couldn't.

This is common on your 987 Boxster. I have a 987 Cayman S, and it does that as well. Other owners of 987s have told me that their cars also do it. If I hadn't known about it before I bought my car, I would've also thought something was wrong. The 986 (1997 - 2004) cars don't do it, but the 987 (2005 - 2013) car do, at least with most tires. It's because the larger footprint of the larger (18", 19", and 20") tires and the Ackerman steering geometry of the 987 suspension makes the tires want to "grab" the pavement when the tires are at the extremes of the steering angles. ike84 is also partially right.

Good point Racer, I forgot to mention checking the toe differences with the wheel turned over (ackerman geometry! I never realized there was a name for this). Here are the factory alignment specs, including the tire differences when turned. Sent from my POCOPHONE F1 using Tapatalk

Would there be any reason someone would modify the Ackerman geometry of the toe-in of the alignment... say for track? Or maybe the previous owner kissed a curb? My car is under CPO warranty and I’m considering taking it back to the dealership for alignment. This is really annoying. Advice please.. Thanks.

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Track guys will modify nearly all aspects of the suspension alignment depending on the track and performance expectations. Did you ever get the alignment checked by an independent shop? Most places will do that for free. Just make sure they give you a printout showing the numbers. If your car is still under CPO warranty and the dealer seems like a good guy, it may be worthwhile taking the car back and asking them to go for a ride with you to get their opinion on it. Sent from my POCOPHONE F1 using Tapatalk

It wasn't until I had a race alignment on my CSS that I noticed this happening. I have .09 toe in the front and 0 toe in the rear along with my negative camber. No issues with my LE, as it has a factory alignment. Both have the same sized tires.

Well, I took it to the dealership and the service advisor told me this is called “tire scrubbing” and it is completely normal. I googled this to verify. My previous 2 Boxsters never had this problem. Tire scrubbing is more noticeable in cold temperatures. I guess I’ll have to live with this.. very annoying.

PROBLEM SOLVED, I bought a set of Faulkens, problem completely gone. Not only that, they are quieter, last longer and half the price of the PZeros. Never again will I consider buying PZeros. They are also hard to find. Who in there right mind would buy PZeros?