315/30ZR18 R888 tire on a 12" rear rim
#16
Race Director
So did you guys run 265/305 ? Like this ?
265/35/18 : 25.30
305/35/18 : 26.41
That's pretty close to the stock diameters :
235/35/19 : 25.48
305/30/19 : 26.20
but with a bit more rake.
One advantage of the 255/315 is the smaller diameter gears you down by 3% and lowers you a bit, but those are small effects :
255/35/18 : 25.00
315/30/18 : 25.44
It seems maybe 11.5" rear is actually the more general purpose size.
265/35/18 : 25.30
305/35/18 : 26.41
That's pretty close to the stock diameters :
235/35/19 : 25.48
305/30/19 : 26.20
but with a bit more rake.
One advantage of the 255/315 is the smaller diameter gears you down by 3% and lowers you a bit, but those are small effects :
255/35/18 : 25.00
315/30/18 : 25.44
It seems maybe 11.5" rear is actually the more general purpose size.