tire sizing question

[Toyotaxtreamteam]

ok i got a quick question, on ties for example, 205,75r,15 '
the 205 is width and the 15 is size of the the rim, now whats the 75 and whats better 75 or 60 or 50

 

[jdub]

Go here:
http://www.discounttire.com/dtcs/infoTireDimensions.dos

Lot more info:
http://www.discounttire.com/dtcs/infoHome.dos

 

[Toyotaxtreamteam]

ok mine right now is 205,60,15 i think i am geting for the rear 275,50,15 do you think it will fit the rim by this

 

[jdub]

You're using 15" wheels on a Mk III? That's different...the stock sawblades are 16". Most of us go to a 17" or 18" wheel.

Ok...go here:
http://www.discounttire.com/dtcs/infoTireMath.dos

It's a tire size calculator. For example, I wanted to go with an 18" rim and need to know what tire would fit.

I filled in my old tire size: 225/55/16
I filled in tire sizes for an 18" wheel...I wanted a 275 width, so I looked at different aspect ratios (or section heights) to closely match diameter as possible. Turned out 35 was perfect...it was -.16 difference in diameter. So, I went with a 275/35/18.

Now the only other answer I need was offset...read up on it and decided a 38mm would work. And it did.