Some of you may know about this site....
But for those who don't it's a great place to visit. It's basically a piture gallery site of what different size / width / profile tyres look like on
diff J rims.
So say you want to know what a 165/40/16 tyre looks like on a 7.5j rim then scroll down the page an look at the images
www.tyrestretch.comIt seems to be a bit glitchy though !!
Enjoy