225x45x17 on front 17s
 

I have OEM 17s all around with 205x50s fronts and 255x40 rear. Will 225 fit the fronts? Want to reduce understeer a bit and they don't match my rears that are stickier. Thanks

Absolutely, I am running that size myself on both my summer street tires and my track tires. I love it. If you call tire rack they will confirm that is an approved tire (at least they did to me when I ordered my first set.

Steve

What do you have now on front and back?

I have 225/45-17 front and 255/40 -17 rear and it works great

You can even fit a 235 on the stock front wheel (if the tire of your choice doesn't come in a 225).

Boxster race cars run with a set of rear wheels also on the front to get 255/40/17 on all four corners. But you'll need adjustable sway bars to dial out the oversteer (because that front end has huge grip with a 255 up front). I repeat, don't do this unless you have adjustable sway bars or it will drive like a drift car.

I did this a few months ago. Wanted to swap from the Pirelli P-Zero Russos to Michelin Pilot Sport 2 all round so decided to increase the fronts from 205/50/17 to 225/45/17. I like it. It makes the steering a bit heaver in my Boxster but makes you feel like you have more front end grip. Was worried I might affect the balance on the track but i've done two events and all seems good.

from what i've found, 225 front good match for 255 rear, and 235 front goes well with 265 rear. about to try 245/275 next.

Thank you guys, the PO had put Yk580 on fronts probably just to sell the car before me. Rears came with Sdrives. Just want to match tires but with better grip up front.

I wouldn't put 275/35 on the rear with 3.2L or smaller due to loss of torque multiplication.

285/30 is slightly shorter than 265/35 & works well as long as you use 10" wheel & there's no clearance problems.

275/35/17 actually works just fine on a Boxster if you are going for 245/275 stagger. The diameter is 24.7" so even a bit shorter than a 255/40/17.

http://www.tirerack.com/tires/tires.jsp?tireMake=Hoosier&tireModel=R7&partnum=73 5ZR7R7

Oh, I was talking 18" I thought that's what Radium King had.

Tirerack is blowing out the BFG Rival Gen 1 in 225/45 255/40/17. I've heard S drive is a good high perf summer tire as well and affordable to boot.

hah, i do. here are my calcs for an 18" wheel (i was trying to ensure front/rear height differences were under 3% so as to not mess with ABS):

225/40 (25.1) 265/35 (25.3) OEM
235/40 (25.4) 265/35 (25.3) current
235/35 (24.5) 265/35 (25.3) 3.3%
235/35 (24.5) 265/30 (24.3)
-
245/35 (24.8) 275/30 (24.5) proposed
245/35 (24.8) 275/35 (25.6) 3.2%
245/40 (25.7) 275/35 (25.6)

ps, sorry for the hijack to the op.