tyre markings

i just read a post by this guy who referred to the tyre markings on his mercedes and they made absolutely no sense to me.This might be due to the different systems used in different countries.i think this is a good opportunity to discuss the different terms used in our respective countries/systems so we can better understand in the future.

heres the typical denomination in india:-

1) P235/75 R15; Treadwear 480 Traction AA Temperature A (this is uniform tyre quality grading); 105 S (service description); plus of course the manufacturer's name and the tyre name

-The P designates that the tyre is a passenger vehicle tyre. Some other designations are LT for light truck, and T for temporary, or spare tyre

-235 is the width of the tyre in millimetres (mm), measured from sidewall to sidewall.

-75 is the aspect ratio.i.e tyre height is 75% of width.(tyre height not rim dia.)

-The R designates that the tyre was made using radial construction. other tyres are made using diagonal bias (D) or bias belted (B) construction

-15 designates the rim diameter.

-the tread wear no. is only a rough indicator since noone knows what conditions you ride under.but higher the no. longer your tyre will last.

-Tyre traction is rated AA, A, B or C. It does not indicate the tyre's cornering ability

-The tyre temperature ratings are A, B or C. The rating is a measure of how well the tyre dissipates heat and how well it handles the buildup of heat.

-service rating has two parts first one corresponds to load rating and second to speed rating.both nos. have to be tallied with charts to get actual figures.

This might seem stupid to the pros but im sure there are some amateurs out there who might find this useful.