hi everyone,
my vz commodore has 225 x 50 x 16 in tyres put on by the previous owner. The tyre placard on the driver door says 205 x 60 x 15 in, but overall diameter of the tyres should be the same or pretty close i thought.
Any way, when the speedo in the dash is compared to our navman (newly bought) the car speedo reads 5 - 10 km more than the actual speed as per the gps. Because the correct speed is not sure i may get a speeding fine.
Is my car speedo is wrong? And how can i adjust it please?. Your help is appriciated - thanks.