195x65 is pretty close to 200x60, but if your speedo was calibrated for
225x60 you'll certainly have some error when you switch to snows.

To calculate the error, use this formula for your snows and your funs:

tire diam.  =  rim diam.  +  (width * aspect ratio / 1270)

 {1270 is a combo conversion factor; works like this:

 TD = RD + 2*SideWall height (there are 2 sidewalls, top & bottom)

 SideWall height = width * aspect ratio, but W is quoted in mm,s
 so must be converted to inches, and aspect ratio is %, so must
 be converted to a fraction; hence:

       TD = RD + 2*(width/25.4 * aspect/100); 100*25.4/2 = 1270}

{I got that formula from this NG, and now I'm giving it back.}