So I switched out my worn rear Pilot Sport 315 25 19 for Nitto Invo 315 25 19 due to non availability of the Pilot Sports. Still have the size appropriate Pilot Sports up front, 235 35 19 . Now the PSM is intervening all the time in casual cornering and if I try to drive aggressively in turns forget about it the PSM intervenes hard. So pretty much have to drive the car with PSM deactivated.

Anybody have experience with this and can you explain why? I thought it might be a break in or temperature deal with the Nittos but nope, I ran the car hard in the mountains this past weekend, got the tires good and warmed up and turned the PSM back on and it intervenes all the time, downright unnerving....

 

it's a solid bet that in spite of you having driven a bit, the rears are not sufficiently scrubbed in, and the ecu is detecting the tread depth difference "mismatch" front to rear. plus, used pss front and new nitto's rear isn't the best combo in the world for an awd car.. that said.

they'll still settle down after continued driving, provided the sizes are within "spec" for the awd system. i have no idea any longer what sizes are optimal when running 19's.

just keep driving. it'll ( should?? ) stop, once you wear some more tread off of the rears.

 

I'd give them more time as well. Here is how you can get a better set of 315/25's in the future.

https://www.6speedonline.com/forums/...ng-import.html

 

I had a similar issue with new rear tires on 1/2 worn fronts (Falken brand). I ended up changing out the front tires and no PSM issues.

I'm now running much stickier Yokohama AD08Rs and will change out all 4 at the same time when the rears are done, regardless of front tread wear.

 

Honestly man it could be new tires needing to be scrubbed in but i've seen some whack *** failures with the Invo's over the year and it's just way behind any modern PSS/PS4S or the new PZero.

I think it probably won't change much after 500 miles and it just down to a compound that's behind the times.