Odometer Error Constant At All Speeds

I would have to get 215-45-19 wheels to compensate for 10% higher speedometer readings

 

I've tested my speedometer against my GPS on several trips now, from 25 MPH to 60 MPH (had a brief freeway trip last week), and I did not see any difference between what my speedometer read and what the GPS reported.

 

The difference on my torque app:

The speedometer display reads 50 mph.
The computer reads 48 (per torque).
GPS reads 49.

Take the speedometer for what it's worth. Just know that if you are ever pulled over, you were really speeding.

 

Your speedometer reading slightly low is causing you multiple problems, LOL? To the point that you swap tires?

Sorry, just don't understand the issue. As has been noted: it's mandated for speedo's to read low.

 

Our snows (195/65R15) are bigger OD than the stock 215/45R17, so we have a similar seasonal shift to our speedometer, somewhere between 1~2 percent. Sorry, but I just can't get worked up about this. Most cars on the road have a similar "error" in their speedo, again, because it's mandated.

The car's overestimating mpg by about 8% bugs me more, but I still manage to get to sleep.

 

Since I don't speed, at least not intentionally, I have no problem with that. Even if I were speeding and got caught, I wouldn't have a problem paying the consequences for my choice to break the law.

 

The UN document is also implemented in the Australian rules (not sure if you were including us in "Asia").

I haven't done extensive testing but a quick test I have done had a calculated speed of 105.6 km/h when the displayed speed was 110 km/h.

See also Speedometer accuracy - reads faster than real mph? | PriusChat

 

63.36 mph vs 66 mph. That's what I've observed as well.