Robofc

Hi,

I just bought an RS America with 7&8 x 17 wheels. The stock configuration is 205/50/17 and 255/40/17 tires.

I was thinking of putting 225/45/17 tires on the front to reduce low speed understeer.

Does anyone have any experience with tire sizes?

Also, I was thinking of Yokohama advan AD08 or Continental extreme contact dw tires. Any thoughts?

KaiB

Where and how are you experiencing low speed understeer?

Babalouie

I'm running the AD08s in 215/45 and 255/40 and are very happy with them. They do seem to be a step up in grip from the Pilot Sports I had before. I'm not so sure if upsizing the front a little did anything to reduce the understeer tho.

Frank 993 C4S

I run 225/45s on the front and the 255/40s in the back. Sorry, no experience with these tires or low speed understeer on my 964.

964Q

Regarding low speed understeer, are you referring to auto-x? From my experience, a good "sporty" alignment will refresh the way the car drives and can reduce that front end push. I can't speak of the AD08's as I've never driven on them, but I read they are a great summer performance tire.

Robofc

Thanks for your help. I spoke with Rob at S-Car-Go today who said that he would put Toyo RA-1s with 225/45/17s on the front. Any experience with RA1s?

KaiB

To be honest, this means nothing at all until you let us know how you use the car and how it is responding for you when you use it.

No such thing as too much information here....and it's also OK to say half of the equation is looks.

chakka

Used to run RA-1's, Nitto NT-01's(less expensive and I think just as good) in 225 & 255 on 17's for the track. Nice set-up for that, but also have suspension work, corner balanced and aligned. As others have said, more info needed as to your cars use. Going from a performance street tire to an R compound is a big difference.

Frank 993 C4S

Depends what you will use the car for. If it's mostly track, the Nitto NT-01 are good. I go through two sets a season.

I would not recommend for anybody to put these tires on their car if you're doing mostly street driving. These tires don't do well at cold temperatures on the street and they are loud as in truck tires (maybe even louder). When I first got them, I thought my wheel bearings went bad.

Robofc

Hi,

There are 170 turns between my house in Bolinas, CA and my son's school in Mill Valley, CA in Marin County. That is the only place I drive the car and low speed understeer, especially when doing downhill comes up.

I usually run negative 1.5 camber in front to help. But I assume going up from 205 to 225 will help as well.

Frank 993 C4S

Don't go for R compound tires. Try the 225s up front.

KaiB

As far as street tires go, I'm a big fan of the Dunlop Star Spec Z1.

RSAErick

Here's another vote for the Dunlops. Great grip, even when cool. Won't hold up well long term with track duty in the heat - but perform track duty pretty well if not too hot.