Speedometer slow Issue

[Shak]

My speedometer is always around 5-8 km slow.

Struggling infront of cameras specially , ended up slowest car in the road since not sure what kind of speed I am driving.

Any help on this please ? Thanks in advanced.

[kevinj93]

The response from Toyota will be "this meets Australian Design Rules".

ADRs allow the speedo to read 3 percent plus 4 km/h higher than the actual speed but must not read lower. This is tested at several specified speeds.

I have the same error in my Yaris. Interestingly, the data from the OBDii port agrees with GPS speed readings.

I have asked a few time on the forum before, but no one seems to have determined if the speedometer has any internal calibration adjustments.

[Mister]

'Muricah vs Ozstraylyaa...

https://www.youtube.com/watch?v=7n6DEYqVDEY&t=4s

https://www.youtube.com/watch?v=XpA57X4Em8Y

Who wins? :laugh:

[David C]

Only quick fix would be to swap in bigger outer diameter tires to match the speedometer and odometer, at least on the front wheels.

My Michelin Defender in 185/60/R15 actually gives me 3.5% above the speedometer reading while my Gislaved Nordfrost in 175/65/R14 give me 0.5% below reading.

I haven't thought about cross referencing the OBDII port with GPS data. What I did was log both GPS speed and distance on a 200km stretch of uninterrupted driving with low traffic to log a constant GPS speed of 100km/h on cruise control along with the GPS odometer and timer and the road side mile markers, and compare to the car odometer reading.

So in your case you'd want bigger tires, like a 195/55/R15 instead of a 185/60/R15. You can find data online that would tell you how many revolution per miles or KM your current tire is spec at and use that to determine how many more RPM your bigger tire would need to be to match your speedometer. For example my Michelin Defender was spec at 876 revolutions per miles and the new tire I'm buying this spring is also rated at 876 RPM (BFG Advantage T/A Sport in same size).

[Fluxtasy]

The response from Toyota will be "this meets Australian Design Rules".

ADRs allow the speedo to read 3 percent plus 4 km/h higher than the actual speed but must not read lower. This is tested at several specified speeds.

I have the same error in my Yaris. Interestingly, the data from the OBDii port agrees with GPS speed readings.

I have asked a few time on the forum before, but no one seems to have determined if the speedometer has any internal calibration adjustments.

Yeah the GPS speed readings on my phone & OBD2 port are the same too with around 1 sec lag from phone. Previously someone explained to me that the issue is that our speedometer is analogue and it does not display the info accurately.