Rain tire closeout at hoosier
 

I just got a set. they are Continentals, but made by Hoosier, 265/645-18 at 100 each plus 15 shipping. Just scroll to bottom of page.https://www.hoosiertire.com/discontinuedtires.htm

they also have continental 285/645/-18 slicks at 110 each. I might get a set or two.

how do you figure out he size on those, can never remember

285/645/-18=285/35/-18?

Yeah I can't figure out the sizes either but I was wondering if those Continental road tires would even heat up on a 40-60 second auto-x course? Probably not

645 is tire height in mm., not aspect ratio, 25.4"

285/645R18 is between 30-profile and 35-profile.

285/30R18 should give you a tyre diameter of 628.2mm and
285/35R18 should give you a tyre diameter of 656.7mm

so the aspect ratio is somewhere around 33%

My formula for tyre height in mm is:

2*((Section Width * Aspect ratio)/100) + 18*25.4

These would almost be worth buying and having shipped here as the price is actually pretty good, even allowing for freight and import taxes.

RB