I did a search and read a couple of old posts about it.

Whats everyone's thought on 265 Kumho's for the rear? For me buying a swaybar is not in the cards, so would using these with the 225s provide a nice alternative for track days, or should I stick to something else?

Thanks!

 

The 265s are reasonable for helping with oversteer. They are a full inch taller so that hurts acceleration a bit. They probably aren't the fast ticket but for your described scenario they should be about right.

Think seriously about a bar, however. The Saner bar looks like a reasonable low-cost solution although maybe not ultimately competitive. A couple hundred bucks is less than 2 tires...

 

You may also want to wait a little while. I spoke with some Kumho people that promised the new Escta V700 would soon be offered in some enticing sizes for the S2000. Namely a 235 (front) and a 255/40 for the rear. Those rears with the normal 225 fronts should take care of the serious oversteer problems as well as help gearing.

 

I know the tendency is to stuff the widest tires that fit in the wheel wells on a car but the factory still tells you that the tire should be spec'ed for the wheel size. The sidewalls bend in, deforming the contact patch. Tire pressures can help some but then there's the stiffening effect that you get from lots of air.

Anyone have actual test results proving that proper sizing vs. over-sizing produces significant differences?

 

265's work great.....had much success with trying them at Sears Point and streets of willow this week. lap time improved over 17/255 which has stock diam. i run front Mugen bar and 4.44's.
no rubbing with rear lowred 1/2-3/4 inch on stock +65 offset rims.
go for it.