Wheel size

[Vultch]

To wheel experts, what do the various codes mean,

I know tyre wise 245/40/17 is a tyre 245mm wide, 40% profile on a 17 inch wheel.
But I'v seen ET38 and a host of other codes regarding offset etc..

what does it all mean

[Bogus]

http://www.carbibles.com/tyre_bible.html

Its all in here somewhere

Bogus

[Dara]

Et38 is the offset of the wheel...basically the center of your wheel is et0 if you move out from the center towards the face of the wheel you have positve offset an if you move in towards the back of the wheel you have negative offset....so if you have et -38 its 38mm's back from the center at the back half of the wheel an if you have et +38 its 38mm's towards the front of the wheel from center...its how far your wheel mounting surface is from the center of the wheel its measured

[Doc B]

Et38 is the offset of the wheel...basically the center of your wheel is et0 if you move out from the center towards the face of the wheel you have positve offset an if you move in towards the back of the wheel you have negative offset....so if you have et -38 its 38mm's back from the center at the back half of the wheel an if you have et +38 its 38mm's towards the front of the wheel from center...its how far your wheel mounting surface is from the center of the wheel its measured

Thanks for that explanation. I always wondered exactly what it meant.