I'm going to replace the rears only because I have a leak in the passenger rear tire. I just wanted to know if this was a reasonable idea.

I'm thinking of buying the RE960AS Pole Position (Potenza) it has good reviews and stats from tire rack and is going for a good price. I'm just getting the OEM size b/c I hear that 245/40 is bordering on too much width for the stock wheel to handle and creates a soft sidewall for turn in. So would getting new rears in the stock size adversely affect anything important?

Thanks.

 

you will be fine. if anything, get 235/45/18, just a little more grip cant kill

 

235/45 will be taller than the stock tire. If the DSC/TCS systems see a difference in diameter front to rear it will trigger much sooner. Do you really want to be driving normally and have the DSC keep kicking on?

Stick with the same size as the fronts. Of course, if the leak is repairable, I would just fix that. Then you can just save your money and replace all 4 at the same time which is a much better idea.

 

That seems to be exactly what is happening with my car since I installed a pair of General Exclaim UHPs in the stock size on the rear only. The DSC keeps kicking in even in normal street driving so I have to remember to turn it off after every start.

At first, I thought the problem was the Exclaims, as if they were not as sticky as the Dunlop 8090s, but now I realize that trying to get the last few thousand miles out of the original front tires is a mistake and I will get the other two Generals installed up front.

 

not every 8 has dsc

 

245/40 fits the wheel without difficulty, there are no clearance issues, and it holds fine on track & autocross. If your rears are less sticky than the fronts, you'll get some oversteer that you aren't used to. If you have a lot of tread left on the other 3 and don't want a mismatch, Tire Rack can shave a tire down to match tread depth for $25. I did that after I got a nail in the sidewall of my 050's.

 

a 245/40/18 would make the tires stick out?
i was looking at this set of tires, you think it would feel and look better?
http://www.tirerack.com/tires/tires....e1=yes&place=0

 

At 245, the tire sidewalls are out past the wheels just a little; it does give the advantage of helping to avoid curb rash. It by no means bulges. Here's a shot of my 245/40 18's (Bridgestone Potenza RE050A Pole Position)

The downsides to 245's are cost and fuel mileage. Some people complain of less sharp turn-in, but I didn't find that to be noticeable.

As to the Sumitomo's: it's a cool tread pattern and a fantastic price. They won't give you the same level of performance as the OEM tires, but if you aren't autocrossing/tracking the car and aren't a lunatic on the road, you shouldn't need that last 5-10% of grip. They're half the price of the 050's on my car and the Star Specs on my garage floor.

BTW, it's worth reading through the scads of reviews on Tire Rack when choosing a tire. There are always some outliers, but you'll get a good feel for the strength's & weaknesses of the tires that the surveys don't always bring out.

 

aren't all the b stock guys running 245/40's?