Hankook Tires = PASM Intervention?

Was at Buttonwillow last wknd, burned thru my Bridgestone rears and the only set of tires I could find in Buttonwillow in the right size (285 18 rears) were a set of Hankook Ventus V12's. Just went for a spirited drive through the Marin headlands and PASM seemed to be kicking in on any mildly aggressive turn. Does it make sense that it would be the tires? Are they really that bad? I didn't really have an option and they apparently came in 2nd place in a Car & Driver summer tire performance test. Any help appreciated.

I put a new set of the V12's on a few weeks ago and haven't had a PSM activation yet - although weekend driving in DC & Northern VA traffic: a) really sucks, b) makes me miss driving in Marin & up/down the coast, c) I probably couldn't activate PSM if I tried unless I took a freeway on ramp curve at 90. Ok, rant over - sorry that didn't help you but - in all seriousness I've been happy with my new rubber in limited but slightly spirited driving around here. Others in a better position to comment?

If you are running different tires front and rear PSM will kick in much too often.

lbuckly: Good to hear things are working fine for you. I think dresler may be onto something with the different rubber front/rear. dresler: Yes, I have Bridgestone S02's up front and the Hankook's out back so that may very well be what's going on. Thanks fellas

Absolutely that is what is happening! One of our members put those on the rear of his 996 Turbo and the car became nearly unsafe to drive. Mis-matched tires will screw up the PASM because the characteristics of the two different axles is so great the system can't keep up with the inputs.

I've been on a full set of the Hankooks for a few months now and I've been very happy. No more or less PSM than with the Bridgestones that came before. I agree different front and rear is a possible cause. Maybe also that new rubber is sometimes a bit slick.

PSM (not PASM) is sensitive to rolling diameter of tires. Stay within 3 percent of the diameter of the OEM tires to avoid freaking out PSM TC and ABS.

Interesting regarding the 3% rule. Just checked and seems that I am within tolerance. And yes, honestly the car feels unsafe to drive with these rear tires on. Must be an issue between mis-matched front/rear tires. To those who have the Hankook's, have you tried tracking the car with them or no? If so, how did you find them on the track?

I tracked my car with the Hankooks (full set), and found them to be very good for the price. They're very predictable, and held up well over the three days that I've put on them. The one issue that I did notice is that my PSM/ABS lights went on intermittently, soon after I put the set on. I'm wondering if the diameters aren't exactly what they should be, which in turn throws off the system. -Jon

If the tires are new you may have just had to scrub that outer coating off the tires as fresh tires aren't at their grippiest until that coating wears off and the tires have gone through a few heat cycles. Your PSM may have been going off due to the difference in grip and you exceeding the rears.

Turn it off....PSM is like a annoying mother in-law sitting in the backseat telling you to slow down.

How do the tires feel for you otherwise? I like the V12's a lot so far (about 1,000 miles), but they've got a pretty deep tread that might initially be a little squishy. Mine's a '99 so I've got less e-issues to deal with I guess, but the tires themselves inspire confidence at the limit and feel very neutral.

For the strek-strekeenth time can we please get our acronyms right around here?!? PSM = "Porsche Stability Management" (i.e. juggles your rear brakes to keep you from spinning, blinks a "PSM" light at you when it thinks it is saving your bacon). Was either optional or standard on the 996 depending on model. PASM = "Porsche Active Suspension Management" (i.e. fancy shocks controlled by a computer that try to improve handling and ride quality all the time... it's never "off." PASM was introcuded in 2005 and was NEVER AVAILABLE ON ANY 996). Stepping off soapbox now. Please continue discussion. OP: Porsche specifically recommends against running different brand/model tires front-to-rear. Doing so certainly throws the stock handling balance into disarray if the tires happen to have significantly different handling charateristics... as you have discovered.