Quick Tire Size Question

[BennyL]

Hey guys. Quick newbie question. What do the first 2 numbers in a tire's size mean? Does it go width/sidewall height/rim size?

If I'm going to buy a set of rims with 235/40/17 tire on them, would it be unwise of me to put 205/40/17 tires on?

I'm asking cuz the tires that come with the rims don't have much tread left, and there's someone selling 205/40/17's for a good price.

[ZiMMie]

http://www.walmart.com/i/tle/tirediagram_500.gif

[BennyL]

thanks zimmie

so, i was basically right?

so if i go to a 205 tire, it will be significantly narrower. is that a bad idea?

[Mystikal]

Narrower AND shorter. Do not run that size tire.

[BennyL]

okie dokie