Date: Wed, 11 Feb 2004 16:37:49 -0500 From: "Fred W." <Fred.Willsnopsampam myrealbox.com> Subject: Re: Speedometer wrong on '93 SAAB 9000 CDE
"Johannes H Andersen" <johsnopsamfitter.com> wrote in message news:40294DCC.613F8E85nopsamfitter.com... > > > ngwcaa wrote: > > > > They appear to be 195/65x89 - does that make sense? > > Yes I think it means 195/65/15 since those were originally fitted to > my 93' 9000 CSE. However, there may be variations due to wheel/tyre > options, but these will have very similar rolling diameters. I don't > think that would result in any perceivable change in the speedometer > scale. So either the problem is psychological or something else. > You could time the distance covered between fixed mileage points. Actually, there is very little difference. My '93 9000 CSE has always had 205/60-15's. I see that Tire Rack Web site shows the stock size for a CS is also 205/60, but a CD gets 195/65's. I also do not see a CDE listed, for some reason, but I imagine that there was one, though who knopws what the OEM tire size was. The diameter of a selected 195/65 is 25" and the same maker's 205/60 is 24.7". That equates to rotations/mile of 831 vs. 841 or a 1.2% difference. So at 60 miles per hour your speedo may be off by slightly more than 1 mph!! yikes... -Fred W