I figured I'd go out last night and actually see what the RPMS at speed was, since this is really what everyone wants to know, and there has been so much questioning the ratios.
With the belt drive 70 MPH = roughly 3850 RPM...from what I have seen the 18 is about 3750 at 70...and the 17 is about 4250 at 70
Pretty darn close to an 18 I'd say.
