Speedometer not acurate on F10

Anybody notice their speedometer too kind (showing me going 53MPH while my garmin shows 50MPH. From the first day I drove the car I noticed it and took it to the dealer (they claim they tested it, my SA told me it was within specs, +/- 5mph. I understand there is a way to adjust it via the service menu. Do anybody know how to do this ?. thanks

Every BMW I ever owned had this. My Porsche and Ferrari's speedometers also read 3 to 4 mph higher than the actual speed. I recall the reason for this is that there are extremely severe penalties in Europe for having speedometers that understate the actual speed. So, rather than taking a risk of understating the speed, they purposely overstate the speed. I recall reading this somewhere, but don't remember where.

About 10 years ago Car and Driver tested various cars about the accuracy of the speedometer readings. BMW was by far the most consistently optimistic speedometer reading. I have had five BMWs since 1992. Each one has had about he same error in the speedometer. At highway speeds the speedometer is usually about 3mph over the actual speed. I think the error is a percentage, so that the faster the car is going the larger the speedo error.

Originally Posted by John NY

I recall the reason for this is that there are extremely severe penalties in Europe for having speedometers that understate the actual speed. .

Norway is the only European country who regularly condemns its citizens to prison sentences for speeds that seem perfectly natural for citizens of other western countries.
140 km/h on a motor road under perfect conditions is enough to land you in jail for at least 18 days - unconditionally.
And please remember that any license witdrawal is not subject to any court order as in other European countries. The police may even confiscate your license on the spot (you have to leave your bike or car by the road) for 14 days if they only suspect that you have committed a crime that might lead to license withdrawal.

Speed limit Violation Fine (NOK) Fine (Euro)
60 km/h and lower + 1-5 km/h 600 kr 72 €
+ 6-10 km/h 1 600 kr 194 €
+ 11-15 km/h 2 900 kr 352 €
+ 16-20 km/h 4 200 kr 509 €
+ 21-25 km/h 6 500 kr 788 €
License withdrawn + 26 km/h and more Heavy fine, max 10 000kr
JAIL** + 31 km/h and more* Jail: Minimum 18 days

70 km/h and higher + 1-5 km/h 600 kr 72 €
+ 6-10 km/h 1 600 kr 194 €
+ 11-15 km/h 2 600 kr 315 €
+ 16-20 km/h 3 600 kr 436 €
+ 21-25 km/h 4 900 kr 594 €
+ 26-30 km/h 6 500 kr 788 €
+ 31-35 km/h 7 800 kr 945 €
License withdrawn + 41 km/h and more Heavy fine, max 10 000kr
JAIL** + 51 km/h and more Jail: Minimum 18 days

As John NY was saying, this is not an error. BMW intentionally is showing a higher speed. I remember on older BMWs the OBC was showing the true speed and the needle was showing true speed plus aprox. 3%. On F10 (at least mine) both are showing the same speed, higher than the actual.

Originally Posted by mrbombastic

Anybody notice their speedometer too kind (showing me going 53MPH while my garmin shows 50MPH. From the first day I drove the car I noticed it and took it to the dealer (they claim they tested it, my SA told me it was within specs, +/- 5mph. I understand there is a way to adjust it via the service menu. Do anybody know how to do this ?. thanks

I have seen the same thing in all my BMWs (99 e39 528i, 06 e60 530i, 09 e60 550i). And have been wondering if this means that our 50K warranties are expiring prematurely because the speedometer seems to think you are putting more miles on the car than you really are!!!

/a

If you want your F10 speedo to run spot-on, swap out your stock run flats for a set of non-run flats that are 245/45/19 size (assuming your wheels are 19"). That's what I did and now it's exactly correct at all speeds according to my GPS.

Originally Posted by atarighi

I have seen the same thing in all my BMWs (99 e39 528i, 06 e60 530i, 09 e60 550i). And have been wondering if this means that our 50K warranties are expiring prematurely because the speedometer seems to think you are putting more miles on the car than you really are!!!

/a

I had wondered about the same thing on my old X5, but it turns out that the vehicle is smarter than that. The computer knows very well, the real speed and sends the speedo out to lie to you. Frankly, it used to drive me nuts all the time. I'm so glad my 5 is corrected!

Originally Posted by Quacker

I had wondered about the same thing on my old X5, but it turns out that the vehicle is smarter than that. The computer knows very well, the real speed and sends the speedo out to lie to you. Frankly, it used to drive me nuts all the time. I'm so glad my 5 is corrected!

As far as I know, the digital mph readout is also correct. If you reset the (average) mph readout at any time it should show your true current speed.

Originally Posted by ProRail

As far as I know, the digital mph readout is also correct. If you reset the (average) mph readout at any time it should show your true current speed.

I knew that and frequently did just that - sometimes to obsession. With my new F10, the slight increase in tire diameter I got when I went to non-runflats made a perfect correction. After years of driving with an inaccurate speedo, having one that tells the truth is a real pleasure.

Originally Posted by Quacker

I knew that and frequently did just that - sometimes to obsession. With my new F10, the slight increase in tire diameter I got when I went to non-runflats made a perfect correction. After years of driving with an inaccurate speedo, having one that tells the truth is a real pleasure.

Glad I was able to help.

The Beemers show the same optimism. Must be a German thing.

Regards,

Don m

You can make the speedometer accurate through coding. Read the coding thread.

Originally Posted by Stealth.Pilot

You can make the speedometer accurate through coding. Read the coding thread.

Could you give me some link how to do this.

Originally Posted by mrbombastic

Could you give me some link how to do this.

Hi Mr. B

Where in Atlanta. Are you? I'm in Sandy Springs and waiting for a 550 to arrive at Global.

Regards,

Don M

I am in grayson.

Originally Posted by mrbombastic

Could you give me some link how to do this.

You need to read the coding forum. It is not simple. It's not hard (unless you have my laptop) but it's not a few clicks.

Here is BMWs SI on the subject.

http://www.bimmerfest.com/forums/att...8&d=1337563756

Well, guess I got lucky with my 5 then. Since day one the error has only been +2mph from about 25mph to any highway speed I've yet attempted (that's with a 40 series tire on a 19" rim). All verified by two different makes of smart phone and two different GPS speedometer apps. BTW it's not a "BMW thing" every make of car ever owned or driven has had this positive error built in, even before the overly strict speeding penalties came about.

Interesting read. In all my years of driving, I never even noticed this and the idea of "true" speed indication never even crossed my mind.

I did the coding changes for both my F10 and F25 and neither worked. Both speedo's are still showing 2-3 mph faster than my Garmin. I have also checked my Garmin against my other non BMW's and it is spot on with their Speedo's. I may have missed a code but followed what is posted on the forums. Is there any coding needed to be done outside the KOMBI folder?

Originally Posted by samillerfl

I may have missed a code but followed what is posted on the forums. Is there any coding needed to be done outside the KOMBI folder?

No, unfortunately you are correct. I tried to recode mine too and did not working. With any luck one of the coders will figure it out.

Darn, I was hoping I was wrong.

Hey Needs, can I borrow your laptop for a fortnight?
I am on 245 18 Inch Mssp non runflat and teh speedo is 4 to 7 km/h over GPS measured speed.

While correcting this there are some other things I might like to code..

Mine reads 5% high. It was my understanding that BMW does this intentionally.