Fair enough. I have to imagine any new tire worth a crap is going to be quieter than my horribly cupped stock bridgestones. They blow. I am more wondering about the difference in height than the width. A shorter tire will typically have worse ride quality.
rough math:
225 x .40 = 90
245 x .35 = 85.75
255 x .35 = 89.25
255-35 is closest in height to a 225-40, but the 245-35 is not waaaay off.
edit:
Here’s Dan GSRs math, not mine
225/40 (18) = 25.08 in diameter
245/35 (18) = 24.75 in diameter
255/35 (18) = 25.02 in diameter
Modified by T.D.B. at 10:20 AM 3-10-2010