Odometer Accuracy?

I have been wondering the same thing about my '14. It seems my commuting distance has gotten shorter in this car vs. the '11. The 3% you all have been kicking around is about what I have been considering as well. How far off does it need to be for warranty repair? Is there an easy way for service to confirm the margin of error?

The two ways to confirm it for a specific trip is to:

A) use a GPS unit to compare to the trip odometer

B) use Google Maps for the route to compare to the trip odometer

A third way is a little harder and slightly less accurate, is to drive on a highway that has marked distances. The hard part is you have to go far enough to "synch" to the error close enough to be able to be accurate. If it is over-reporting as you suspect, then you drive 30 miles indicated on the odometer, and it ticks over to 30.0 miles just as you pass the 29.3 mile marker.

NeilBlanchard said:

The two ways to confirm it for a specific trip is to:

A) use a GPS unit to compare to the trip odometer

B) use Google Maps for the route to compare to the trip odometer

A third way is a little harder and slightly less accurate, is to drive on a highway that has marked distances. The hard part is you have to go far enough to "synch" to the error close enough to be able to be accurate. If it is over-reporting as you suspect, then you drive 30 miles indicated on the odometer, and it ticks over to 30.0 miles just as you pass the 29.3 mile marker.

Click to expand...

I was asking if there was an easy way for a Service Department to determine the error margin. I have already done my own tests. But don't want to get into a p...ing match over if I need to pay for it or if it will be warranty.

Sorry, I misunderstood your question.

I'd be surprised if the service people at a dealership can delve into the code for this. I think they would have to do a test like we have done.

I'd be very surprised if there was a way to adjust the odometer calibration. If there was a way to change it, then it would allow people to dishonestly tamper with the odometer.

This is only a guess. I don't have any info on what is adjustable and what isn't.

Bob

Bob said:

I'd be very surprised if there was a way to adjust the odometer calibration. If there was a way to change it, then it would allow people to dishonestly tamper with the odometer.

This is only a guess. I don't have any info on what is adjustable and what isn't.

Bob

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I would say that it's 99.9% that it can't be done without being hacked, which means the dealership won't do it.

If it was too far out of spec and something needed to be done a dealership would just replace a whole bunch of parts and document the ODO change with the state.

NeilBlanchard said:

The two ways to confirm it for a specific trip is to:

A) use a GPS unit to compare to the trip odometer

B) use Google Maps for the route to compare to the trip odometer

A third way is a little harder and slightly less accurate, is to drive on a highway that has marked distances. The hard part is you have to go far enough to "synch" to the error close enough to be able to be accurate. If it is over-reporting as you suspect, then you drive 30 miles indicated on the odometer, and it ticks over to 30.0 miles just as you pass the 29.3 mile marker.

Click to expand...

I think the highway marked distance method would be the most accurate. GPS units calculate distance by taking the distance between points dropped every so often, and are not inherently accurate. Sort of like estimating a circle with a 100-sided polygon. Close, but not something to use as a golden standard. Highways, on the other hand, are carefully built and surveyed by engineers and surveyors with laser equipment.

In any case, 20-30 miles is FAR too small of a sample to be using. I would not estimate odometer accuracy with any distance shorter than 100 miles.

I checked both GPS and Google Maps, and they were the same. And, when you do the math on the tire diameter, it was also within a couple of 1/1000ths percent.

I'd say that is very accurate.

Measuring on the highway with markers ever 1/10th mile is not very accurate unless you go a long distance. You have to go far enough to have the trip odometer trip over to the next 1/10th as close to the moment you pass a marker as possible - otherwise you have a known error. You have to round down after you estimate the timing. I have done this several times, but always in my ICE. In the Leaf, the distance you can drive this way is shorter, so the accuracy will be lower.

An update of sorts: we now have 205/60-16 Nokian Hakka R2 winter tires on our Leaf S and even though the 25.7" OD is larger than the SV / SL tires 25.5" OD, the odometer is still reading a bit too high. I measured 122.9 miles on the GPS while the odometer registered 123.6 miles. Which a bit less than 0.5% over, but still a bit off.