981 Boxster S tire size....35 or 40?
 

So for my wife's new-to-her Boxster S, it's looking like we'll be needing some new tires for the car sooner than later. Right now she's running (all almost dead with one damaged) Goodyear F1 Asymetric at 235 35 20/265 35 20. I'm thinking of giving the Conti Extreme Contact Sports a shot...but that front tire at 235 35 20 is like a rubberband. I see that doing 40 vs 35 all around is an OEM option...but I thought I'd ask you guys to get any feedback you might have. She has the standard suspension...no PASM or X73. She does have Sports Chrono but I forget if that does anything to ride height.

As far as driving behavior...she will be driving the car both on highway and side roads (say...30/70 split) around 200-250 miles per week once the weather gets better. No tracking. And she's not a nut-case on the road, she's a quick, but good driver.

Many thanks for any feedback.

John

I think the only option on the 20" wheel was the 35 profile. The 40 profile is for a 19" wheel. That doesn't prevent you from doing it. I just don't recall a 40 profile tire being an OE option with the 20" wheels. Presuming you go up from a 35 to a 40 profile front and rear it shouldn't screw with the brake controls (ABS/ESC/TCS), but it's going to throw your speedometer off by a small amount (2.5mph at 70mph). Tire is going to be 1" larger in diameter, so you'll lose 1/2" in clearance to fenders.

+1 for the Michelin PS4s. Their wet grip has rave reviews (I have no personal experience in this because I don't drive my Boxster in the rain) and it should be a big plus in Seattle.

As for the size, the OE for the 20" wheels is 235/35/20 for the front and 265/35/20 for the rear. The 40 profile will bring up the overall diameter nearly 1" which is well over the commonly accepted 3% tolerance. I would stick with the 35 profile or seek to go down to 19" if you are not comfortable with the 35 profile.

Thanks guys. I run the PS4S on my GT4 so I'm familiar with the performance. And yeah...amazing. Thanks also for the 35 vs 40 comments. Lamenting those...

My wife's driving is far more -cautious- and between that and this vid:

...the Conti's seem like a darn good option...including in the rain (again...see vid...holy crap).

Great driving!