Speedometer problem
 

I discovered that my speedometer reads ten miles faster than the actual speed. Needless to say I was disappointed when I realized that the turn that I thought I was taking at 90 mph was actually 80. Any ideas on how to fix?

Thanks,

Leo
86 Carrera Coupe

I think that was standard at least for the 85-89 911's. You can get it recalibrated by a company like North Hollywood Speedometer.

Adjustment