Why Do My Stock 15's Measure......

[julien98]

Hi. I'm a newb. I have the 5 star alloy stock rims that come with the gt model. they are said to be 15's, however I measured them and they are a little over 16 inches! does this mean if I get 17's they will measure 18 on the outside?? HELP!!!

[Cheese Toast]

Look at the tire size, it's printed on the sidewall something like P195/65/15 the last number (15) indicates your rim size.

[julien98]

If anyone who has them sees this, what do your 17 inch rims measure for diameter on the outer most part of the rim.

[GTSTISL]

julian-i just measured my GT wheels and they are also about 16 1/4"..hmm not sure why, but i kno it has to do with where you measure. i think if you measure from the inside its 15. BTW-nice car Obsidian 04 GT Sedan. same as me :)

[BobMs_wht2k2]

The 15" wheel means the inside diameter of the tire. The rim has to be "oversized" to support the tire. There is a lip on the inside and outside of the wheel that is there to hold the sidewall to hold in the air. That's why looking at a wheel without the tire it will look like an "H".

[GTSTISL]

yea, thats what i was tryin to explain, just couldnt
http://www.hako-didactic.de/deutsch/news/news04/images/hako-1297.jpg

[blupupher]

And the same thing with the width. A 7" wide tire will measure 7.5-8" on the outside, but measured where the bead sits, it is 7".

This is a 15x7 rim:

http://users2.ev1.net/~nlhoyt/Jeep/pics/rim1.jpg

But as said, it will be stamped on the inner part of the rim:

http://users2.ev1.net/~nlhoyt/Jeep/pics/rim2.jpg

[julien98]

Thanks!