Hi, My speedo reads 70mph when actually I'm doing 62 mph. Checked by my GPS. What needs to be changed? I suppose I need to figure out what the rear axle ratio is first. How can I do that physically? There must be a way to measure the tire circumference, etc. Any suggestions?? Don Lattimer #3M5759 V6 Willits, CA
Message
Speedometer error
2001-10-10 by Don Lattimer