Incorrect fuel gauge reading???

[Texasota]

On a related note about intentional miss-calibration, there's an international agreement that speedometers must read 5kph (or about 3mph) high.

 

That is the first I have ever heard of that. Can you elaborate or point us to documentation?

[murphy]

 

 

 

On a related note about intentional miss-calibration, there's an international agreement that speedometers must read 5kph (or about 3mph) high.

Mine is 1 mph high according to my Garmin gps. Speedometer accuracy changes as the tires wear down.

[talmy]

 

That is the first I have ever heard of that. Can you elaborate or point us to documentation?

 

A coworker pointed that out and showed the standard about 10 years ago. However it looks like it may have changed to 4km/h recently. See Wikipedia article http://en.wikipedia.org/wiki/Speedometer#International_agreements which has a footnote pointing to the actual standards document.

[Texasota]

 

A coworker pointed that out and showed the standard about 10 years ago. However it looks like it may have changed to 4km/h recently. See Wikipedia article http://en.wikipedia.org/wiki/Speedometer#International_agreements which has a footnote pointing to the actual standards document.

Interesting reading. These standards/regulations state that "The indicated speed must never be less than the actual speed" and they cap the amount of inflation that is allowed in the speedometer reading. But I did not see anything where it required a specific amount of inflation. I could have missed it.

[corncobs]

Mine is 1 mph high according to my Garmin gps. Speedometer accuracy changes as the tires wear down.

That's probably the reason why they need to start "high"