The 245 is supposed to go on an 8 inch wheel. Look it up, I did. I have 245/50's on my 16 inch ponies and I wish I hadnt gone that route. The rear is squirrley like its on marbels. If you corner all of a sudden it feels real loose in the rear. It never felt that way with the 225/55's that were on there. I say stick to the 225 or get a wider rim, you will be much safer driving it on the street. Also the at the big end of the track mine is swaying a bit in the rear, its not scary really, but I am only trapping 97mph. That was at 35psi also, same as I run them on the street. Mine are nitto 450's, not DR.