moswissa

Hey guys,

so I replaced the rear tires on my 991, but the fronts were still ok maybe 50% thread left. I went with the same brand and size as before. I notice my traction light flashes very often when I am taking on/off ramps. Never used to behave this way. Even thought I am not driving it aggressively. It’s usually when I’m entering the turn.

Does the car need to relearn ? If Is it because the rear tires have more grip compared to the front, causing the systems to be overly sensitive. Maybe I should have replaced all 4 tires

Dark_horse

What tires did you have before and what tires did you change it with? I change my rear tires a lot more often than my fronts and that’s not going to be a problem. Also check tire psi, too much and you will have less traction.

JW911

The last time I saw someone post this same problem, it was because the tire shop inflated them to max pressure instead of comfort pressure (thus being about 10psi over inflated) I never trust a tire shop to properly inflate tires. I have never had a shop properly inflate them, not even a dealer.

DC911S

If it’s a 4S or 4, changing just the back will throw off the traction control due to the differences in the circumference

Levy

yep. was dating a gal a while back who did/experienced this on her awd car (not a P). i hear/read 2/32 is about the max difference tire treads can have with modern *awd* cars. much more then that can cause driveline issues as well as traction control/stability control and abs electronics to get confused. if the OP has awd, 50% is way too big of a difference.

moswissa

I changed it to the same tire and brand which were falken 510s. It’s the 20in set up and actually I did notice tire pressure is 50 in the rear.. maybe that’s the issue

moswissa

hmm, mines a S2

jfischet

yes, 50psi is too high. check inside the drivers door or the manual for comfort and sport settings.

JW911

50? Way too high. Problem discovered! Unless you are regularly driving 160 mph, you want the comfort pressures front and rear which is in the owner's manual. (Not on the sticker inside the door).

moswissa

yeah comfort pressure is not on so the car didn’t mention it over inflated, I think the previous pressure was 42? I’ll deflate them. I’ll also check the owners manual. Thanks

DC911S

The drivers door jamb will have a sticker with the pressures on it.

subshooter

Let us know if this solves the problem.

the_buch

Also, a bit slippery to start until the greasy mold release agent wears off, though this only takes 100 mi max?

BSO

Have a '19 C4S with RWS and a MT.

Replaced just the rear tires at 10k miles, had no issues with any warning lights/messages (nail in one, plus shoulder wear, so did both).

Further, caught another nail in one of the fronts with around 10k miles of wear and replaced just the damaged one. Again, no warning lights/messages. It has been 10k miles since the single front was replaced and everything has been just fine.

Tires are Michelin PS4S all around.

All the tires have lots of tread left and the two fronts have very similar wear.

As stated, the culprit is likely the ridiculous hi tire pressure they put in. I've made a sign to hang from my rear view mirror, stating leave the tire pressure alone at the comfort setting, for the techs to see. Also, the sign also states don't wash my car, thank you very much.

moswissa

will do, I adjusted the tire pressures based on the door frame, 36psi front and 44 in the rear. Ill keep you all informed