how to read tire sizes...325-18-25?

[nudymeyer6]

that was just for example i do not know if that is a real tire size. anyways, what i would like to know is what the different numbers in a tire size mean/how to read how big a tire is by the numbers. for example, what does the first # stand for? what does the second # stand for? and what does the third # stand for? TIA.

[jnolte]

Okay 255/35/18 for example


255 is width of tire

35 is how thick the rubber is, 30 is like a rubber band


18 is the rim size

[nudymeyer6]

thanks j.

[omegabenz]

255/35/ZR18

255 is the width in millimeters as said before

35 is the profile of the tire meaning 35% of the width of the tire so the sidewall is .35 times (255mm)

Z is the speed rating meaning 149 mph and faster

18 is the rim diameter.

[Renn 208]

Originally posted by nudymeyer6
thanks j.

hope you read omega's response.

Also, as I've posted before, the tire rack has a ton of great info

http://www.tirerack.com/about/techcenter.html

[nudymeyer6]

THANKS!! , there is a bunch of good tire info on tire racks website! i would recomend looking at that website to anyone interested in tires. i learned a ton from that website! thanks again Renn 208!