Discontinued tires question.
 

Hi all,

My "new" car came with badly worn rears so I need to replace them with an impending track day coming up.

Current tires all around are Dunlop SP SPORT 9090. The fronts have a lot of life left in them.

It looks like this tire is discontinued.

I searched around and it seemed like mixing rear/fronts has mixed opinions.

Any suggestions on?:

1. Change them all.
2. Stay with the same family (Dunlop) but just replace the rears.
3. Put something different on the rear that is the same type of summer/extreme tire. I have Bridgestone Potenzas RE760's on my Audi which I really like but obviously that is a way different application.

Cheers

Gareth

how much tread depth is left on the front ? if it's marginal may be worthwhile changing the full set.

i use the Pirelli P-Zero Rosso N4's very happy with them, the handling, the wear rate is a little on the low side, but nothing earth shatteringly bad.

I'd recommend changing them all. If you have different tires on the front and rear (or even the same kinds of tires but one set new and one used) you will have different grip levels front-to-rear.

Opinions
 

will vary as we don't know your level of experience on the track, what kind of track you'll do (DE versus competition, length, speeds, etc), how much track you plan to do, how old the fronts are, what their tread depth is, etc.

I'm guessing that an experienced racer wouldn't be asking. So I'll answer with the safest answer for road use ... 4 tire change even if you have to go with cheaper tires. In CO you get weather and the deepest tread is the safest. For the track, there are such things as track tires and shaved tires that have more grip and are safer except in the rain.

Can experienced track folk mismatch per axle by design, sure. AXers sometimes do. But they know what the effect will be and are safer in handling the results.

(I know the $ feeling...just replaced my 4 because of age for $1060 or so.)