27-11-2015, 07:04 PM
You say 3-4% out but at what speed, is it 3-4% at 70 or 100mph (where most people check) but what about at 20mph or 50mph?
For testing you could go out and hold the car at every 500rpm then note the speedo speed and gps speed (on a flat road of course) and then that'll show if and where any major discrepancies are.
For testing you could go out and hold the car at every 500rpm then note the speedo speed and gps speed (on a flat road of course) and then that'll show if and where any major discrepancies are.