tire size explanation FAQ

I need an explanation on reading Tire sizes?

Dec 10, 2009 by Alex S | Posted in Other - Cars & Transportation

Can someone explain the difference between 265/70/R17, 265/65/R17, and 265/60/R17 and tell me what the middle # (70, 65, 60) means.

just to add to what everybody else has said, aspect ratio is the number representing the percentage of the width, that is the height of the sidewall. so in this case, the first tire's sidewall height is 70% of the width. so basically, the 3 tires vary

rataflimmy | Dec 10, 2009

the middle number is the sidewall aspect ratio. first # is the width of the tire in MM...third # is the tire/wheel diameter.
Mr Blaze | Dec 10, 2009

Rims size explanation?

Oct 14, 2008 by Cur1ous | Posted in Maintenance & Repairs

What do the numbers mean? ie 16x6.5JJ and how does it relate with the tyre size?

16" is the diameter. So you would use a 16" tire only.

6.5" is the rim width measured from inside of outer rim lip to other inside lip. (where the tire beads seat)

"JJ" means nothing. Virtually every

Frankie Coletta | Oct 14, 2008

16x6.5JJ

16 is the rim diameter, 16"

6.5 is the rim width, 6.5" (Although if you measure the rim lip to lip it may seem larger)

JJ... not sure, but it doesn't sound important. Make sure you get the
Stu C | Oct 14, 2008

Why do tires have both metric and standard units of measurement?

Mar 01, 2011 by bully66 | Posted in Engineering

Can someone give me a brief explanation how and or why tires sizes (width and height) are in metric units yet the rim size in standard? Example 195/60R15 195/60 are in mm yet the rim size in inches.

It is tradition. There are some full metric tires that have rim sizes in mm too but they are rare. Some BMWs used the corresponding metric wheels but getting tires for them was frightfully expensive. Most owners of these cars just changed the wheels

goober | Mar 01, 2011