ChrisD

I have original D90s 6Jx16 front with 205/55 R16 Conti Sport Contacts on, but for some reason the PO has put on the rears 215/55 R16 Mich Pilot HX on the 8Jx16 wheels?

I understand that the correct sizes (original spec) would be 205/55 front and 225/45 rears, although I have seen 245/45 quoted for them.

I plan to replace the rears to 245/45 Contis to make them the same brand as the front, even though there is still a lot of tread left. Thoughts?
Also how much difference does the aspect ratio make and what are the limits with stock suspension?

joey bagadonuts

You'll want to get the same brand and model of tyre. There are a couple of generations of the ContiSport Contact's which feature different tread design and compounds. Mixing models may result in undesirable handling characteristics.

With a 205 front tire, I'd stick with a 225 rear to prevent the car from becoming too undsteery. The bigger rubber out back would increase the car's tendency to push.

Finally, if a decent street tire is all you're after, then you may want to consider replacing all four, given the price for a pair of Conti's. Some of the popular economical options include the Kumho Ecsta MX's and Yokohama AVS ES100's.

To learn more about tyre specs (like aspect ratio), take a tour of the Tire Rack website.

ChrisD

Thanks for the input. I will check out the link.

malc elliott

Note that original spec rear tyre size was 225/50/16, not 225/45/16.

Michael Gibney

Joey Bagadonuts,

Your reply really interests me as I have a tyre "problem". I have 90 C4 coupe with 17's 205 fronts and 225's rear Bridgestone Potenza SO3's all round and boy are they disappearing fast!

I love the grip - but hey 6 to 8000 kilometers (3700 to 4900 miles) from the rears is hard on the pocket.

I just finish explaining the dip in the bank account to "she who must be obeyed" and they are ready for new ones again. I do drive hard and I have had the alignment checked and all ok.

My question - you recomend two brands of tyre - Kumos and Yoki - and you say they are good for the street. Can you give a general opinion about how they would compare to the Bridgestones for wear and grip in the dry? Wet is not too much of a problem as I drive slow in the wet no matter what.

Hope you can help - thanks.

Michael Gibney

joey bagadonuts

G'day Michael!

My take on the Yok's and Kumho's come from secondhand accounts gleaned from Rennlist and the Tire Rack site. I did see a rather quick BMW E36 at the track, however, running on the Yokohama's and they performed quite impressively considering that I was using the Michelin Pilot Sport Cup R compounds (1K USD for four ).

If you want to lean more about the wear history on these tires, I suggest you research the customer reviews for each tire found on the Tire Rack site:

Kumho Ecsta MX
Yokohama AVS ES100

The filter options allow you to review Porsche-specific feedback but you may want to consider the BMW comments as well as those offered by owners of other performance-oriented cars, e.g. Corvettes, Miatas and Audis, to get a complete picture.

BGLeduc

I have had decent luck with the Kumho Ecsta Supra 712.

They are extremely cheap, and the wear has been decent. I have had them on the car since I acquired it (about 16,000 miles ago), and just replaced the rears which were approaching the wear bars. The fronts have a long way to go.

Lost of variables in tire wear, I suppose, but I tend not to push on the street to the point where I will experience understeer or oversteer) as I prefer to blow my tire budget on track tires where I can drive like a maniac in a nice, controlled environment!.

YMMV.....

BGL

PC2

The Yokohama AVS ES100 are pretty good budget tires. The only thing I don't like about them are the noise. They are horrible & loud! You'll have to rotate them every 3000 miles to keep them quiet.

Performance wise they are pretty good for street and occassional DE. Although these tires tend to get greasy during DE events, they still maintain a fairly good grip. A word of caution if you'll be using these for the track. The ES100s does not scream until you've passed their limits. (Don't ask how I know.) So you'll have to take some time to get to know them before you push them hard.

Wear are good, I've gotten 15,000 miles (Street & 2 DE events) out of the rear and the fronts have about 45% left.

JasonAndreas

On the rears you should be running a minimum tire width of 255 when you have 17" tires, the 225 size was only approved by Porsche for 16" tires. There is no reason you can't get 12-15,000 "street" miles from a set of S03s.