Calibration of indicated mph, miles, and duration?

[bwilson4web]

This afternoon I found the tripmeter indicated mph, 74.3 mph, was 2.9% high over the distance divided by time, 72.2 mph. In the Prius community I found it was a problem with tire revs/mile and easily fixed with properly sized tires. Has anyone done a similar study on our i3?

Thanks,
Bob Wilson

 

[jadnashuanh]

From what I've heard, the EU requires the speedo to read 2mph high. The dealers won't calibrate it to be more accurate. I have not looked to see if it is a programmable feature if you were to get the software to deal with that and learn how to reprogram you car. Long time ago, Germany required it to be quite accurate, as you might expect from them, but being in the EU, they have to abide by what the community dictates and we get the fallout.

 

[PhilH]

From what I've heard, the EU requires the speedo to read 2mph high.

From my memory (and Wikipedia says the same) EU regs require that the speedometer must not indicate a lower speed than you're travelling, but may indicate a higher speed. Wikipedia says 10% plus 4 kph. Manufacturers would therefore never provide a precisely accurate speed measurement in case something (e.g. tyre diameter) affects the measurement and it goes low: they always err slightly on the high side.

 

[websterize]

In other BMWs, the speed corrector can be deactivated via coding. In the i3, look for 3000 > BC_V_KORREKTUR in the BKOMBI module. In testing with an iPhone GPS and Waze.app, however, deactivating the "korrektur" appeared to have no effect. The car still an indicated ~2 mph above actual speed.

 

[gt1]

True speed is easily checked with a GPS unit or a phone app.

 

[justanotherdrunk]

Speedometer in both my BMW cars read 3-4% high

i3 and 128i

The R1150GS Adventure motorcycle I had read ~7% high


all 3 vehicles odometers were very accurate with <1% deviation

:ugeek:

 

[bwilson4web]

Good deal!

It sounds like the trip meter mph is accurate which is what I've been using to validate my models.

Bob Wilson

 

[busaman]

uk law say it can read up to 10% high (VOSA) but can not read low....