N Rated Tyres

[AVI_8]

I've had my 911 for 6 years now, it had fairly new Conti Sports when I bought it, It was time to replace the tyres this year so I did some research and saw online several Continental tyre types (Conti sport 2, Conti sport 3)

Having read the description on the continental website I bought 4 sport 3 tyres as this was the newer type. 255/40/17 and 205/50/17

It wasn't until after the tyres were fitted that I found out that Porsches are supposed to have N rated tyres, the guy at the tyre centre told me that although the tyres I bought are good tyres, they're not rated by Porsche.

I wouldn't have been too bothered about that but when driving back through country roads I felt that the car didn't seem to be as sure footed as before, it's not that it lacks grip but the best way I can describe it is that it feels that there is more flex in the sidewall, I've always found the 964 to be a great car through corners, very easy to balance it with the throttle, now when I do that it feels as though it wants to oversteer even though the tyres are not physically skidding if that makes sense.

I don't know if I'd just got used to the feel of the car with less tread and now that there's more tread there's more flexing? I've owned a few sports cars over the years and It's not something I've noticed before with other cars.

I'd be interested in hearing if anyone has found this after fitting new tyres, I paid £555 for them and have a feeling that I'm going to have to go and get another set and get what I can get for the ones I've just fitted on ebay.

An expensive mistake possibly! But I don't want to compromise handling.

The pressures are ok I've always used 45 on the back and 35 on the fronts as I found higher pressures on the rears gave a sharper feel.

Some input from some of you track focused guys would be good thanks

 

[Steve Brookes]

Two things:

1. New tyres will always feel a bit slippery for about the first 200 miles while the releasing agent works off.

2. You're running the wrong pressures. 17 inch tyres on a 964 should be set at 36 cold front and rear. The pressures you are using are for 16 inch tyres. Furthermore, with the current warm roads, your rears will have gone up to something like 50 psi while they're set as they are. The car will feel very loose!

 

[AVI_8]

Thanks Steve, I'll give them a few hundred miles before making any decision, regarding the pressures, yeh I know that 36 is the recommended pressure, strange but to me it felt less loose with the rear tyres set to a higher pressure.

I know the standard tyres are meant to have 46 at the rear, also the 18 inch tyres, couldn't quite understand why the 17 have a reduced pressure, I'll give it another try though.