freetrog

I've put about 14k in 2yrs on a set of Yokohama AVS. They still look good and have plenty of tread left but boy are they getting loose on the road. Tire performance has dropped significantly over the last 6 months - braking = using ABS more often, going = go through standing water on a corner accelerate out in 1st or 2nd and it'll break loose. Wet = don't ask.

I know - performance tires = shelf life, blah, blah, blah. But, I'm thinking that 90% of porsche drivers drive on the public roads and simply can't drive to their tires capabilities, and given that most people don't do more than 5k per year - the tires will go hard before they're worn out.

I'm simply interested in how many other people change out seamingly good tires to get more grip - or do they slow down / take it easier? Right now it's fun running on slippy tires and I'm looking around for another set. Is this common to other brands too?

Please - don't blast me. I'm not a nun on the road, I push it. I'm a normal guy who loves his car but also has a family and can't be throwing $$ around.

GeoC2cab

High,
I would say ur ready for new rears, I havent used Yoko's but 14K is alot of miles,
I drive the way u do and my SO2 rears are almost gone w/almost 10K on them(2 1/2 yrs), just recived new set of rear SO2's before they sold out. Try some new rears if ur fronts are still in good shape, its normal to go through 2 sets of rears to 1 set of fronts. Happy skateing!

Jim Michaels

I suspect that you've worn down to a part of the tire that has a harder compound that is not as grippy as the compound nearer the top. This harder compound is nearer wear bar level and helps extend rubber life so that you won't suddenly wear down to air. Actually, that may be another urban legend, but it was what I read *after* I decided to autox my Yoko 008Ps with little remaining tread years ago. I thought the tread had worn down to "just right" for autoxing, but spent the afternoon steering like crazy instead. I think it's Yoko's way of saying "time to re-tire."

Adrian

What Mr Freetrog is describing is very common. Especially with the 964 C4s but I know many others who own C2s and Turbos who say the same thing. There is in my opinion a definite time when a tyre, despite having good remaining tread and apparent even wear, just goes off.
My P7000s (just for a test) went off at 5000klm. They will be removed for next summer.
The problem is that when you feel this, the confidence level drops.
Why the tyres fail like this is a complicated subject. Has to do with uneven heat cycling. Trying to use the tyre before it is heated up and many other factors. The rubber ages and goes hard. Hard rubber, no grip. There is no guaranteed solution to this problem except to purchase more suitable tyres. They cost more, the wear out faster but go off slower.
To answer your question. For me, when the tyres have gone off it is time for them to be changed. I live in the mountains and need good tyres. Wet weather performance is first to fail,
Ciao,
Adrian
911C4

freetrog

Adrian

I think you might have hit the nail on the head. I bought these tires - ran about 150 miles and then did a DE. I'm thinking the lack heat cycling messed them up.

Whoops.

Jim Michaels

I liked what Adrian said even more than what I said. 14k miles over 2 years and the tires have no doubt hardened some. Many drivers might not even notice because they don't ask a lot from their tires. But I don't think that not heat cycling street tires before a DE would cause them to suddenly lose grip 12 or 14k miles later. I think that pre track heat cycling effects are much more subtle. I have about 15k miles on my S02s and they seem to be working as well as ever. But these aren't the tires I autox and track either.

Jeff Curtis

You got it, just changed out the rears, from RE-71s to RE-730s...the rears were worn to nubs.

What a difference! So much in fact that the car now drives like dookie! I no longer have any "spin" when accelerating, especially since installing a limited slip diff. about a month ago.

"Fresh" rubber certainly makes a difference. I am going to go ahead and replace the front RE-71s (although there is PLENTY of tread left on them) due to the adverse handling effect the new rears have had on the car.

The rears stick so much more than the front now, I actually experienced quite a bit of understeer on my favorite ramp last night. I could feel the front wheels sliding through the corner.

In all fairness, I feel the need to inform readers that I have a "Cup" style suspension that I installed shortly after purchasing the car, replete with 25.4mm and 22mm sway bars...so having two different kinds and condition of tires on the car is VERY noticable!