I'm prepared to take a beating for asking this question. I need to replace my rear tires MPS2 (fronts are the same) and the front are nearly new. I want to just put two new MPSS tires on the rear which would leave a set of MPS2 on the front. Thoughts?

 

I am running that at the moment for a similar reason. (I ran PSS all round and then put PS2s on the front for free) I race once a month, and it does not feel unbalanced in any way. It felt like I had less understeer after changing the fronts, but I think it was just because they were new. The result would probably also vary depending on your suspension setup.

 

Thanks

 

No, bad idea. Lots of threads on mixing tires.......

 

Yes I've seen these, but aren't these tires very close to one another? I would think that the differences would be so slight as to not be problematic. Please correct me as needed.

 

I think the only thing we can say with certainty about both types of tires is that they are produced by the same manufacturer. The PS2 technology is a generation and, what, perhaps 10 years older. Tire chemistry changes, technology changes, rubber compounds change, etc. etc. Any similarities with the PSS are likely small, I would think. Perhaps the folks at Michelin could provide a more objective comparison.

That said, if you're not using your car for performance driving, particularly the track, and if you don't tend to drive in the rain you might be okay. I once replaced a rear set of RE-11's with another set of RE-11's and the effects on the street with new rears and slightly worn fronts was noticeable and concerning. You should know very quickly if you need to go to a matched set of PSS's. Good luck!

 

Great advice! Thank you.

 

Your suggested install will be fine. While not OPTIMAL. These are cars, not surgical instruments and the AWD and steering systems etc., are not sensitive enough to dectect the minute differences in rubber compounds and tread designs in what you are suggesting.

If that were the case...You could not have 305 on the rear and 235 on the front??.... So, it is designed to have 235 mm of rubber on the road for front....305 mm of rubber on the road in rear...but if you get an almost identical tire with a different rubber compound and tread design, you will lose control of the car and crash....it will be so unstable that it will not be drivable!! Doubt it....

Everyone has an opinion and is an expert This is just one opinion. And when I was in college (long ago) and worked in the tire industry...believe me...the tire companies have all sorts of scare tactics to get you to by 4 tires instead of two...and the $800 tire instead of the $200 tire...But your call...

Good luck...
DC

 

Any other opinions? I'm in the same boat now. What did u do?

 

I respectfully disagree. I purchased my 996tt in November. It had PSS 235/35 19 on front and PS2 315/25 19 on rear. My PSM activated frequently on our freeway entrance and exit ramps driving at moderate speeds. So much so, I almost sold the car! I also wasn't pleased with the rims as they were 3 piece, leaking and wrong color! I removed wheels and sent them out for refinishing. When I received them back, I had purchased new PS2's all the way around and mounted them. The car now handles like a P car should! I have yet to set off the PSM! Just for comparison, I reinstalled the PSS' (which I had mounted on a set of Ruger Mesh wheels I purchased to run temporarily while my wheels were getting refinished), went for a ride and instantly set off the PSM! So I can tell you from my recent experience that mixing PSS and PS2's is not a good thing to do!

BTW...I'm no expert! But going around a curving entrance ramp to a freeway at 50-60 and having the PSM engage out of the blue has a very high "pucker factor"! It scared my wife to the point that she wouldn't ride in it because her "opinion" was it sucked! With the proper tires that feeling is gone and now I actually enjoy driving the car!

 

Is it recommended no, can you do it and be OK, yes. It all depends on how you drive. I have driven in the rain with two race slicks on the left side of car and street tires on the right side and was OK.

The only issue you'd hit is if you push the car close to or past its limits and that's when things get "interesting" as all the electronics on the car are calibrated for a certain weight and adhesion distribution on these cars and may interfere in a way that puts the driver in a weird situation. The calibration tolerances are a lot less than I expected (I think "Vantaredoc" post found the same thing). I have had similar experiences as him when mixing tires and just had to drive at reduced speeds to compensate.

 

I've been running PS2's in the front and PSS in the rear with no issues whatsoever. Michelin lists the PSS as a replacement for the PS2, so this is even a recommended replacement from Michelin. However, the wear indexes are considerably different, so you would think there would be a considerable traction difference. Reality is, there doesn't seem to be and the PSS's get even better traction than the PS2's.

 

The other factor here, which does play into it is that tyres go off after 4 years, dramatically reducing the stickiness. So whilst your fronts don't wear as quick as the rear, doesn't necessarily mean they are not ready for replacement. Check the year of manufacture on the side, if it is five years old your should fork out the extra dough.

 

TY. Its a tough choice. Still have 65% left on front ps2. 4 pss vs 2 rear ps2 is only like 100$ more, but feels like a waste. I called michelin and they said it was ok to have ps2 on front and pss on rear, then called me back 5 min later and said it was a mistake and they dont rec matching

 

After I posted this thread I spoke with a rep at Michelin who told me it would be fine to pursue the PS2F/PSSR. No issues thus far (800 miles). I do not track the car.