I looked through the 260 page+ rpf1 official thread and couldn't find anyone with 245/40 front and 255/40 or 275/40 rear. I have rpf1 17x8 +45 front and 17x9 +45 rear with trimmed fenders/lip both front and rear and tab relocated with euro spec camber. It's a 2003 AP1 with big front sway bar and was wondering how people feel about the balance between 225 and 255 traditional stagger and 245, 255 stagger on an AP1. I have KW clubsports by the way at nearly stock height. Would the 245/40 fit fine on the 17x8 front without any rubbing at stock height with negative camber? Would the extra tread width be worth it or would putting a 245/40 on a 8" wheel not be of much benefit since it would be stretched more and thus wouldn't gain as much contact patch over the 225/45 as I would think? In addition the tire would be 2lbs heavier up front as well than the 225.

Thanks!

 

An 8" isnt an ideal paring with a 245 width as the tire would be a bit bulged, so you won’t get all the benefit out of it like you would on a 9- 9.5" and handing response/turn in will be a bit more vague, but ive seen worse combinations. Being your running a bigger bar up front, you would benefit from some added rubber, so I would likely split the difference and go with the 235/40. This would be the best overall accommodation and a good pairing to your 255/40 rear. Slightly shorter profile tire for less sidewall deflection and a wider contact patch over a 225, which won’t be particularly pinched on a 8". Better fender fitment as well

 

I had the same idea but they don't have 235/40 in the tire I want. Only 235/45 and 245/40;(

 

It is a limited size. I believe the Dunlop starspec/z2 comes in this size which is a great tire if your considering an extreme summer performer. Id recommend it.

 

I was hoping the shorter sidewall of the 245/40 would help negate the stretching on an 8" wheel, adding back some lost response and since the sidewall is shorter than the 225/45 it would actually result in more stiffness.

 

Stretching is putting a narrow tire on a wide rim. Bulge is when your trying to do. Puting a wide tire on a narrow rim. Persional ky I would just run a 17x9+45 square setup with 255/40/17.

Stock evo 8/9 rims are 17x8 and countless of those guys run 255/40/17 even though your suppose to have at least a 8.5 inch wide rim for a 255 tire.

 

I already have the 17x8 wheels for the front unfortunately, just trying to decide to stay with 225/45 or move to 245/40 (wish 235/40 was available in the tire I chose as that would be a no brainer). They have a 235/45/17 As much as I don't want to go to that larger sidewall, the little extra footprint up front might help.

 

On an s2k with a front wheel of 8" there is only 2 natural options for the best overall grip and handing performance and feel. The 225/45 or a 235/40. Thats it if your shopping in an extreme summer tire profile. Max summers or all seasons run narrower.

 

The 225/45R17 and 245/40R17 will both fit on the 17X8 and they are within spec so they are not stretched. If you go with the 245/40R17 front and 275/40R17 rear you are going to need to roll the fender lips and run more negative camber. You would also end up with a taller rear tire and could throw off the anti lock brakes.