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BMW 3-Series Speedometer Inaccuracy

26 messages,  Last post on Dec 29, 2012 at 11:47 PM

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What is this discussion about? BMW 3 Series

Messages Page 3 of 3

#20 of 26 odometer by bmwlemon

Dec 10, 2009 (4:26 pm)

my wife's BMW 328i speedometer is off as well. When actually traveling 70mph it reads 75. The odometer is off too. The dealership assured me the two are not connected, but I doesn't matter. According to BMW customer service I can travel 45,000 miles and my odometer will read 50,000 thus ending my warranty. They refuse to correct this problem.

#21 of 26 Re: odometer [bmwlemon] by steveaccord

Jan 29, 2012 (6:35 pm)

Replying to: bmwlemon (Dec 10, 2009 4:26 pm)
I am sure everyone is sleeping soundly on this topic, after all the last post goes back to 2009! That beside I do believe that assuming that the speedometer and the odometers are tracking their respective measure in a connected manner is just plain wrong. Odometers are set according to precise requirements defined by the department transportation and need to be calibrated according to actual mileage, hence the legal implications of frauds connected to resetting it by various means. To my knowledge the odometer has a hardwired cabling to the actual axle transmission sends power to. That is not necessarily the case with the speedometer where, as other have suggested, it may be BMW intention to dupe us to believe we are driving faster than we actually are. That is the case also for my 2008 335xi that clock between 4-5 miles faster than the GPS. I found no such discrepancy between the same GPS and my wife 2011 XC 60 Volvo. Also let's be clear, automotive magazines rely on vehicle outfitted with their highly precise measurement devices when reporting on actual vehicle performance so their data can be trusted and do not depend on the manufacturer onboard dials.

#22 of 26 Speedometer inaccuracy by steveaccord

Jan 29, 2012 (6:44 pm)

Forgot to mention. For what I could tell watching the video posted online the car speed record clocked last year (2011) on German highways on a super modified 540i may have been biased by an inaccurate reading of the odometer. That is what they were showing on the video..the speedometer reaching 237 mph. I am not sure if taking ~ 5mph away, should have they relied entirely on the speedometer reading, would still qualify that vehicle as the speed record holder.
Lastly, speaking about modified vehicles I missed to identify any 3-series related post-market mod forum. I would be interested in such discussions given that I envision to retire my 2008 335xi but keep it as a tasteful track-modded spare car but I do not even know if the AWD model is really conducive to this type of alterations (sure I hope so, F-1 cars are in fact AWD these days). Any chance the gracious Hosts would be able to start one if none is currently ongoing?

#23 of 26 Re: odometer [steveaccord] by busiris

Jan 30, 2012 (11:52 am)

Replying to: steveaccord (Jan 29, 2012 6:35 pm)
it may be BMW intention to dupe us to believe we are driving faster than we actually are.
 
Well, it may sound good the say that BMW is "duping" us, but the facts tell otherwise.
 
European standards are quite specific on the accuracy of speedometers, from a conservative perspective. That means its acceptable to show too fast a speed, but UNACCEPTABLE to show a slower-than-actual speed.
 
Manufacturers can still be held liable for speed differential errors, even if the car owner changes to different wheels, tires, etc., where a sizing difference would have an effect on speedometer accuracy.
 
That is why speeds always show faster than actual on BMW's.
 
For more, scroll down to the section labeled "International Agreements".

#24 of 26 Re: odometer [busiris] by steveaccord

Jan 31, 2012 (4:40 pm)

Replying to: busiris (Jan 30, 2012 11:52 am)
Thank you, I learned something I was not aware of. That would logically explain BMW point on view on overestimating speeds, although if I may point it out, raises question on why not all European manufacturer share such approach. As I quoted the discrepancy does not come up on our Volvo, another manufacturer based in Europe ( I agree owned by non European entities and not an EC member country). I think the accuracy of speedometer was reported by others in the post.....So I am still left wondering if the regulatory European aspects you raise exhaustively justify the speedometer inaccuracies.

#25 of 26 Re: odometer [steveaccord] by lewd

Nov 23, 2012 (9:47 pm)

Replying to: steveaccord (Jan 31, 2012 4:40 pm)
well I just traded my mercedes in on my bmw and the mercedes speedometer was accurate so why not the bimmer?

#26 of 26 Re: odometer [lewd] by dll66

Dec 29, 2012 (11:47 pm)

Replying to: lewd (Nov 23, 2012 9:47 pm)
I have a 1993 BMW 318iS. I've just got back from a trip with it and according to my GPS, the speedometer is accurate.

Messages Page 3 of 3

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