Speedometer Calibration.

[kumistheru]

I am keen to learn how to calibrate speedometers. I have a vehicle that actually shows about 10kms over the actual speed that my GPS provided. Vehicle have installed larger tyres than actually it was originally designed for.

Is there are any tool that I can change speed sensor readings or should I have to work with ECU to tune up RPM values or can it be adjusted in speedometer itself?

Any input regarding speedometer calibration would be highly appreciated.

Thank you.

[2xded]

Hi!
What kind of car? Do you have a device for testing of this car?
Look what size is programmed and installed to replace.
Something like that.
Regards.

[kumistheru]

Toyota Hilux 2009 model. I checked with my GPS speed vs Vehicle's speed reading in dash. While GPS shows 70kms, and speedometer shows around 60kms.

[2xded]

Hi!
You better ask local professionals who have the device Toyota tester or equivalent.
Regards.

[kumistheru]

I am hoping to get answers from DK members as they are professionals too. Hope that the members in DK may know how to calibrate speedometers.