Just wanted to get opinions on what guidelines to most of you use to determine timing of tire change (ie mileage, measuring tire tread using the coin method)

I have 14,000 on my turbo. Tread looks ok still.
I don't drive it too hard... no track time.

What are the implications of riding it a little longer between tire changes?
tx

 

Have you looked closely at the inside edges of your rear tires? Because that's where they usually wear out first . If not worn there, you should be alright for more mileage.

 

I got 15k out of my first set and they were shot, I should have inspected and pulled them off a few k earlier. As mentioned the inside was well worn (car is lowered which accelerates this). No track time on mine either.

 

check the inside edges of the rear tires..

 

Measuring tread, and the overall condition of the tire.. especially on the insides

 

I learned something very cool the other day about Michelin tires (may be the case for other brands dont know). If u look at the very outer edge of the tire u will see a little picture of the Michelin man, run your finger to the first tread and u will feel a bar. When that bar is close or even to the tread itself its time for new tires.<O</O
<O</O

I assume there are other factors that more knowledgeable people will chime in with.

 

1st set - Bridgestones - changed after 7,500 miles
2nd set - Michelins - changed after a further 10,000 miles (was down to metal layer!)
3rd set - Pirellis - still going...

 

Alex, what was your odometer reading when you changed your suspension?

 

Suspension changes have been an ongoing process....

@0 miles: stock suspension (bottom of the range Bilsteins)

Factory front = 132 mm +/- 10mm
Factory rear = 153 mm +/- 10mm

@7500 miles: B16 Damptronics (top of the range Bilsteins)

Front: 134 mm
Rear: 140 mm (bigggg sag, and huge change in rake ie. the nose should be pointing downwards and it was nearly level!)

Reset to 119/132mm F/R

@10500 miles: B16 Damptronics (top of the range Bilsteins)

Front: 112 mm (sagged 7mm)
Rear: 128 mm (sagged 4mm)

Reset to: 117/138mm F/R (-15mm stock)

@17000 miles: B16 Damptronics (top of the range Bilsteins)

Front: 115.5 mm (sagged 1.5mm)
Rear: 135.5 mm (sagged 2.5mm)

Reset to: 117/138mm F/R (-15mm stock) - shouldn't be any more sagging now

 

I get max of 17K on the rears and right now at 28K, the fronts have another couple thousand to go. Just fast/furious street time, no track time.

 

I assume they are the harder wearing Bridgestones and you never accelerate or corner hard in your car? 10k would be the absolute limit for me even in Bridgestones.

Looking at the tread yourself can be deceptive. You need to get the car up on a ramp and look at the rears, specifically the inside edge as this is where it gets worn the most. I had good tread on my last set on the outside edge but was through the material layer, down to the metal layer on the inside edge.

 

Never Bridgestones, learned to stay away from those on my
earlier vette. Agree on the inside wearing faster on the rears,
fabric shows up around 17K....have used only Mich-P2s since
day-1. Seems as I remember, the right rear disintegrates
faster than the left rear and I have the limited slip.

 

Interesting, so you are getting 17k miles (not km?) on the rears with Michelin PS2 (N1 rated)... wow!

I am a big fan of PS2's but I thought this time I'd try the new Pirelli Pzero N2 tyres that came out with the facelift Carrera. They seems to be pretty good from the first few hundred miles usage. Just as good grip if not better than PS2s and quieter IMHO. Wear rate will be interesting. Also, sidewall protection is supposed to be better for the PS2's so I will have to watch out for this.

 

Do a little more research on the Pzeros. I was told by my tire guy that they have a belt shifting problem that makes it difficult to balance as they wear. I know the set that came on my car from the factory were very noisy. Maybe the newer ones are better.

 

My stock rears were running quite a bit of neg camber. Looked good on brief inspection. Took them off to change out to my HRE's and lo and behold, those things were almost bald. Only about 9xxx miles on them.