speedometer calibration

[justanotherdrunk]

the latest android maps update finally includes the speed and speed limits so i wanted to check the accuracy of the car vs the app

i guess 1 mph deviation at 80 is decent

red means toooo fast! :laugh:

https://photos.smugmug.com/Other/MISC-stuff/i-L3tpTKn/0/73f020d9/L/100_8898-L.jpg

:bonk:

[toyotavios_11]

GPS itself wont be accurate too

[ern-diz]

Fun and interesting to look at.

[kevinj93]

GPS itself wont be accurate too

Here in Australia it will most likely be much more accurate that the speedometer. My speedometer shows 80 km/h at a GPS indicated 76 km/h. This agrees with the readings from the OBDII port using the Torque app.

Australian regulations say the speedometer must not show a speed lower than the correct speed, but may read high by up to 4% plus 4 km/h.

Does anyone know if it is actually possible to adjust the speedometer? The last time I touched a speedometer to recalibrate it was 20 years ago on a Jaguar. A previous owner had the trip meter repaired, and the repairer did not correctly reset the mechanical zero...

[NYC-SE]

Yes here too speedometers read higher than actual speed. Annoying. I can deal with a 1mph error (like OP shows and as I have verified on my own Yaris as well) but I've driven some cars where they were off by 4 mph or so. Really annoying. GPS is generally more accurate.

[pjon]

Speedometers here in the U.K. may read up to 10% higher than actual. Never lower.
Thanks for posting the info. re G Maps speedometer. I didn't know it was finaly available. Now found in settings and activated.:thumbsup:

[justanotherdrunk]

Thanks for posting the info. re G Maps speedometer. I didn't know it was finaly available. Now found in settings and activated.:thumbsup:


:headbang:

[hmsailor]

mine is 2mph off. this is from actual speed radar.

[blktiger60]

Unless you are running OEM diameter tires your speedometer will not give accurate info. Smaller diameter tires will give faster speedo readings.

[SECProto]

I just got a new phone with this feature. Confirmed that my speedometer, the roadside speed display thingies, and the GPS all read identical speeds within ~1km/hr

(and I am on OEM diameter tires.)

[Kaotic Lazagna]

Manufacturers have leeway in speedometer tolerances (I thought I remember reading up to 6%, but don't quote me on that).

Yeah, GPS aren't accurate either. You'd have to get one of those fancy devices that they use for record attempts if you want super accurate speeds. lol

[Sia]

Hello, I have a Toyota Yaris 2008 and its speedometer shows a way higher speed. If it is 20 mph it shows 40 and if it is 30-40 it shows 60 mph. Is this something easy I can fix it?