Rims/Tyres

Front axle:
three-piece BBS light alloy rims (10J x 18 ET 1,5)
with central, self-locking wheel nuts
Michelin rain tyres 24/64-18

Rear axle:
three-piece BBS light alloy rims (11J x 18 ET 16)
with central, self-locking wheel nuts
Michelin rain tyres 27/68-18

after working out the #'s 27 seems to be the diameter. what is the 68 number?

btw, download this quaife speed calculator. it's very useful. you can get rpm drops, max speed/gear easily just by inputing the #'s.

http://www.quaifeamerica.com/d...c.exe

 

Those are some weird numbers.... on a normal tire, say 195/50-15, the 195 is the width (195mm), the 50 is the height (50% of the width, or 97.5mm from wheel to outside of thread.) and the 15 is the wheel diameter (in Inches).

applying that to your numbers makes for a seriously tall, narrow tire....

front, 24mm wide by 16.08mm tall
rear, 27mm wide by 18.36mm tall

to get your total height, you would take the tire height *2 + wheel height:
16.08mm * 2 + 18in. (sorry, I don't have my english - metric conversion tables to calculate this right now)


Either that's a wagon wheel, or I'm missing something here, you're not going to fit a 24mm tire on a 10in wide wheel.

 

27/68-18

27 = tread width in cm. (more or less)
68 = tire diameter in cm. (again, more or less)
18 = wheel diameter in inches

See: http://www.michelin-passion.co...ng=EN

 

ahha... so width was about 10.6" and diameter was about 26.8". i thought 27 was dia. in inches. but it came out close enough.

thanks for the info and link.

 

So, is it just Michelin that measures their tires in cm?

and since when did people start spelling tire with a "Y"?

must be a Europe thing....

 

those rim/tire size in my original post are for the porsche 996 gt3-rs. many of the slicks are show in the scheme of thread width in cm/dia. in cm/rim size in " format. it's just not as intuitive as the all english 22"x9"x13"... but now that we know, its' no big deal.

fwiw,

http://www.ghettoracer.com/cars/porsche/gt3-rs/