henkinc

So I replaced my original PS2s (worn LF, rears getting close at 4-6 mm) with MPSS, 19 Inch, 295s in the rear. This is a S Cabriolet, stock. Tire Rack said the turn in would be less sharp but overall recommended them as has this web site.
My impressions after 50 miles:
1. Actually handles a bit better in normal mode. Seems better balanced.
2. Quieter and nicer ride - more solid feel probably due to new rubber depth.
3. Definitely lost the edge in Sport mode. Car feels almost like it is on tip toe when I toss it into the turn on freeway ramps.
So...will the Sport mode handling shake out a bit in a few hundred miles or more? Or am I stuck with a grand touring tire that loses in the twisties.

This is subjective, but comments from you guys? Particularly about wearing in.
Thanks.
Charlie

DC911S

Give them a real good scrubbing and heat cycle.

fuego

Check tire pressure as well. Edmunds had a 2013 in their long term fleet and reported significant changes by playing around with tire pressure.

Macster

Generally new tires require a few hundred miles to lose the more volatile compounds (some related to the stuff that helps the tire release cleanly from the mold) that can make the tires feel a bit "greasy" compared to the the old tires.

However, even after "broken in" and with the right inflation pressure the new MPSS tires may never equal the performance of the PS2 tires they replaced.

I'm not saying this for a fact for I do not know which tire is truly the "best" tire only that they are different style of tires and likely there are performance differences.

BTW, with a "worn LF" uneven tire wear from side to side suggests an alignment problem. In this case it is advisable to have the car properly aligned. An off alignment can affect the car's feel and one blames the new tires when it is the alignment that is at fault.

henkinc

actually, the one worn LF was due to its mileage compared to a replacement RF by the PO (some incident or another) and the alignment is perfect. Car handled great on the old PS2s. Thanks to all of you guys advice. I have thought I might go 2 psi higher on the fronts for more turn in, but will wait until these break in. In any case a couple of extra psi all around would help handling and these are comfortable enough that even for road use (I do not track the car) it might be better. On the PS2s the extra harshness caused me to stick with the 37/44 psi on the door jamb.

extanker

is this your first car/time buying tires

vern1

Well if your running 37/44 with just you in the car then its going to be rough. That's a fully loaded number and most run max 40 hot so probably more like 34/37 cold for normal driving

So are you proposing to run 39/46 on the mpss???

Bruce In Philly

The greasyness from the mold releasing stuff scrubbs off pretty quickly if you driving aggressively. If you go straight to the track with them, just take it easy... tell your instructor. You will feel it and you will know. I think folks get a bit too bent out of shape about this.... one guy I know cancelled a weekend event because he had new tires.... just be careful.

Peace
Bruce in Philly

Fined

As Bruce In Philly said..

its not that big a deal. Get em scrubbed off a bit and it's no problem.

semicycler

This.

The door jamb lists a fully loaded car pressures - two passengers with full luggage. Check your owner's manual for recommended partial load pressures which is for one driver with luggage or two people without. My owner's manual reads 33/39 for partial load, 36/44 for full load.

Bruce In Philly

After you settle on a good starting pressure have some fun and learn by changing by 2 lbs a pop but only do the fronts as that is where you will feel the biggest effects.

Try 2 high, then 2 low (4 less).... you will learn a ton from this simple exercise.

Back when I was tracking my Boxster S, the word was that Porsche purposely under-spec'd the front tire pressure to cause safety-minded understeer. Adding two-three pounds in the front neutralized the handling. Was it true what Porsche did? Who knows..... but adding the pressure in the front did the trick for Boxster owners back then.

Listen to the experienced track rats, then do some experimenting on your own for the next run. The car won't blow up or burst into flames and you will learn. I was amazed at what such small differences in tire pressures did for handling.

The track rats will give you all kinds of real advice.... things like looking at your tire edges to see if the tire is rolling over (underinflated) or not ... lotsa cool stuff to learn.

Peace
Bruce in Philly

henkinc

well, they broke in nicely. Turn in still a bit less nimble than the worn PS2s, but not much and actually once set up the car seems to have more stick to it. Running 36/43 cold and may try 38/43 but it is fine now. And probably still getting better. Plan no track use. Tires are quiet and nice riding.

Thanks, all.
Charlie

mjsporsche

MPSSs are great tires and will likely be what I will replace my PS2s next season.

Interesting that Tirerack mentioned about the sharpness of the turn in.

With all the noise about MPSSs being better than PS2s, I believe that if costs are of no consequences, the PS2s have superior handling "sharpness" and for some are worth the $500 premium (and shorter wear life).

Hella-Buggin'

I ran a two sets of Super Sports and found that 32/36 was a great setting if you're doing lots of back twisty roads. They feel a little soft when first hitting the road but warm up pretty quick and leave enough room to build pressure on a long canyon run to accommodate the pressure build to keep you below the greasy zone.

Sneaky Pete

What ^^^ he said. Henkinc.....too much psi means less grip. Starting out cold at your pressures will put your tires in the 40+ in front and high 40's in the rear.