Tripometer discrepancy

[sdavidp]

I've done a quick search and haven't found this mentioned yet.

Has anyone noticed a discrepancy between the tripometer and odometer?

I've been keeping a record of the odometer and tripometer at fill-ups, resetting the tripometer each time. The other day I noticed that the difference between odometer readings and the tripometer values do not match, by about 5 miles or so. In case I mis-recorded my numbers, I checked my odometer/tripometer yesterday. Since fill-up my odometer showed I've traveled 937-909=28 miles, which means actual distance should be at most (937.9 - 909.0 = 28.9) yet the tripometer showed 30.7.

Am I making a mistake in my calculations or is there an issue here?

[hjsbmw]

I have not observed this myself and frankly have never compared attentively, but there was a thread on this forum along those lines. I don't remember when or by which member though. I think it was also that his trip meter showed a higher mileage than expected or when compared to the odometer.

[badbs101]

I thought I noticed a discrepancy too but thought I was going nuts. I'll have to sync up the odometers again and pay close attention. How is it even possible to design a bike that registers different mileage for the trip odometer when compared to the regular odometer?? Leave it to the Germans!

[Bob Ain't Stoppin']

Check this again when you next fill up so you have a 200 mile test. Obviously, these two should read the same. I've checked my odo against the mile markers on the highway and it's pretty close. But now I don't remember whether I used the trip meter or the main odo. Looks like more research is in order here.

[devguy]

I bought my RR in November and when I brought it in for the first service I had them note on the service order that there was a discrepancy between the two. The odometer read X miles but the trip meter read about 7 miles more. I couldn't see any way for that to happen except for some kind of defect in the system.

I haven't worried about it since as it really doesn't concern me much. I just wanted it noted on the dealer paperwork so if I ever have issues there'll be some paper trail.

I can't think of anything serious that this would cause this but it makes me curious.

Darcy

[psycle.vt]

I noticed the 7 mi difference between the trip odometer and the main one (+7 on the trip) on my wife's new '12 R12R. Showed it to the dealer tech and he was surprised. Of course (as I just discovered after 2 1/2 years) after a 1000 miles, the trip odometer rolls over, so you will eventually lose track of the difference. I have not noticed a discrepancy between main and trip measurement. In fact the +7 difference has remained constant so far.

[sdavidp]

I've confirmed over the last two fill-ups that there is indeed a difference. Yesterday my odometer flipped over to 1124 as I pulled away from the pump. Last time it was 1021, which means I put at most 103 miles on the bike. I'd reset both Trips and at this point each read 107.4.

[deilenberger]

Has anyone checked it vs GPS distance recorded? It may be BMW being cautious with the odometer so it doesn't over-read (leading to class action lawsuits by someone who had a warranty argument with them..)

Interesting factoid: Despite the speedometer being wildly* optimistic (off about 7 MPH at 70 MPH compared to my GPS), the instantaneous speed digital readout (gotten by resetting the average speed while moving at a constant speed) is exactly the same as my GPS speed calculation.

* = The reason I consider it wildly optimistic is - on my Porsche the speedo is dead-nutz accurate when compared to a stand-alone GPS (and the P-car has both a dial/analog display and a digital display.) It's rumored the Porsche calibrates it using the GPS built into the vehicle.

BMW has several times explained the optimistic speedos on their cars as being required to comply with a German law that the speedometer can never read slow, and the offset takes into account all the size tires that could possibly be fitted to a vehicle, apparently Porsche hasn't found that necessary.

[badbs101]

Yep,

My trip meters are logging about 3 miles extra per 100 miles on the main odometer. Weird. They must be sensing the mileage from two different inputs maybe one from the transmission and one from the tires.

Anyone know which is correct the trip meters or the odometer?