I can verify that.... when I removed my 14" alloys and put them up against the
new 15" with the hydroedge, the overall difference in diameter is less than
1/2" -- and that's when you compare a very used tire (no tread) with a new
tire.  So, I believe the math.....

    -Robert
     '91 Carat, 158K miles original motor

------ Original Message ------
> Depends on the overall diameter of the tires.  A 185 14 is about the same
> diameter as a 205/65 15
> 
> ((185*.8*2)/25.4)+14=25.65
> ((205*.65*2)/25.4)+15=25.49
> The above is not precise but shows the profile difference.