Speedometer difference

[Boss330]

Originally Posted by johntomferg

Good article:
http://www.caranddriver.com/features...ometer-scandal

This has been a sore spot for me in my BMW experience with the M5.

I get that any manufacturer may want to have a policy that says their speedometers will be intentionally optimistic as set from the factory. What I don't get is the need for the document posted above [I also received this very early on in ownership], and the desire to prevent the end user of the product from adjusting it to meet their specific desires.

I'm not talking about the lack of adjustment being in the menus, hidden or otherwise, though it would be awesome if it was... NO, I have found 0 dealers that will change it at request and zero Indy's, and I have heard of zero persons that ave achieved correcting it via 'coding'.

Poor decisions BMW...very poor.

Preemptive response to inevitable post about German speedometer laws: I love hearing about German law requirements when I don't live or am not in Germany probably just about as much as Germans love being dictated "realities" of US law when they are not in the US. :-)

The digital display is quite easy to code to read true actual speed, but then it will be off compared to analog speedo and HUD. The link below is a write up on how to code analog and HUD to show true speed on an E60 M5, might work on an F10 as well

http://www.m5board.com/vbulletin/e60.../430570?page=1

[johntomferg]

Originally Posted by Boss330

The digital display is quite easy to code to read true actual speed, but then it will be off compared to analog speedo and HUD. The link below is a write up on how to code analog and HUD to show true speed on an E60 M5, might work on an F10 as well

http://www.m5board.com/vbulletin/e60.../430570?page=1

Aside from the mismatch annoyance, it does not work on the F10 M5. Been discussed at length here and on other forums (Example: http://www.bimmerfest.com/forums/sho...=664231&page=2 ) . Values accessible via E-SYS for this topic can be set but they have no effect. This was the first thing i tried in April 2013.

[johntomferg]

Originally Posted by Boss330

By EU law, speedometers have to show close to real speed, but never less than actual speed.

In the US, it is a +/- 5mph limit. Your speedo can, legally, show as much as 5mph less than actual speed...

https://www.law.cornell.edu/cfr/text/49/393.82

Amazingly my just purchased 2017 Audi Q7 is dead accurate on the display. Kudos to Audi for being able to meet the letter of the law and provide an accurate speedo. BMW needs to catch up on this one.

Ref previous comment about my expectations of being dictated the realities of German law while in the US.
Kudos to BMW for keeping it within the +/- 5mph requirement for US...great job guys! <sarcasm>

Have I mentioned the accuracy of my wife's Jaguar F-Typet's speedometer yet?

[Boss330]

Originally Posted by johntomferg

Amazingly my just purchased 2017 Audi Q7 is dead accurate on the display. Kudos to Audi for being able to meet the letter of the law and provide an accurate speedo. BMW needs to catch up on this one.

Ref previous comment about my expectations of being dictated the realities of German law while in the US.
Kudos to BMW for keeping it within the +/- 5mph requirement for US...great job guys! <sarcasm>

Have I mentioned the accuracy of my wife's Jaguar F-Typet's speedometer yet?

If it helps (insert sarcasm here ) the European BMW's have a much more accurate speedo than what you have it seems. At least all of the Fxx gen BMW's I have driven here seem to be not more than around 1-5kph off (0.7-3MPH). Closer to 1-2kph than 5kph...

So it seems like it is a policy in the US market for BMW to do this?

[johntomferg]

I hope so for the European's sake.

Complete mystery to me what the business motivation is Boss330. It seems very out of step with everything I like about the car / brand. I really don't understand why customers are so accepting of it and why it doesn't receive more attention.

[Lawaia]

My friends i3 has the same issue; 3-4 mph faster.
Heck, at least they're consistent.

[ChrisNich117]

The speedometer is accurate up until 30mph, at least this is what I've noticed from the gps speed from my radar detector.

[johntomferg]

Originally Posted by ChrisNich117

The speedometer is accurate up until 30mph, at least this is what I've noticed from the gps speed from my radar detector.

You guys do know that I love this thread so much -right?

New slogans:

BMW: "Precision at less than 30 mph"
BMW: "You just think you are going fast, until you drive a BMW"

add your own...

[ChrisNich117]

Originally Posted by johntomferg

You guys do know that I love this thread so much -right?

New slogans:

BMW: "Precision at less than 30 mph"
BMW: "You just think you are going fast, until you drive a BMW"

add your own...

Hahahaha

[johntomferg]

Officer pulls you over and says you were speeding.....

You: "But officer are you certain I was speeding? You see, thanks to BMW, my speedometer always tells me I am going faster than I actually am. Therefore I am always going slower than indicated."

Officer gives you a dumb look and then writes you the ticket anyway.

[Maverick997]

Just checked my 911 and its 2 mph faster than advertised.

[Lowflight]

This is my one biggest complaint about BMW. My E92 M3, E92 335i, and M5 are all too conservative. Drives me nuts because I have to think about new speeds to drive at to keep people from running me over.

[AMPowerJ]

I just pass everyone and don't worry about it.

But seriously it annoys me too. It's been consistently with every BMW I've had. I've had GPS radar detectors for years though and I just use that display for my 'real' speed.

[JMD]

All BMWs I've ever owned never had an accurate speedometer! This issue is BMW's achilles heel!

[ur20v]

This is a crazy thread... right!!?

most cars don't use GPS for speed, never have done so you do all know the cars works out speed by using the rotation of either the gearbox, differencial or driveshaft through a wheel speed sensors and you all know tyres are not exactly the same diameter from the factory or between makes then throw in wear and people changing tyre makes and tyre sizes of there choice and this all adds up to a variance... still with me ... also as you drive faster tyres grow and by different amounts depending on tyre pressure, temp and make... now put this potencialy large variance up against the very small variance allowed by a law enforcement speed camera/laser/radar which have to be calibrated regularly... I think you can se where this is going....

Now say you had new or worn tyres of different makes and sizes from OEM or even OEM of different wear, temps or pressures and were sat at an indicated 55 and get pulled would you then say its BMW's fault!? All manufactures over read on their speedo's and the engineered over speed reading is expotential as in gets bigger with speed... its for your own good.

Now if you want to take risk you could set up your scaple car with exact tyre temps, wear and preasures and use coding to calibrate the OEM speedo against a GPS... BUT... thats right GPS isn't 100% accurate either.... now what do you do.

Must be just US cars that come with this holy grail accurate speedo as every ROW car has the ~5% overspeed built into them by law.

[doughboy]

Yeah all cars have to over-read a little and as the tyres wear the over-read will increase due to higher wheel speed at the same actual speed.(or lower tyre pressure will increase speedo reading).

New to worn tyres will make the road "indicated speed" go up by 2 or 3 mph at 60mph.

So to all these guys with "perfect" speedometers they can only be right until the tyres wear a little (or the pressure goes down).

Just maths and tolerances that's all.

[TheHouseWon]

But Your Honor, it didn't feel like 100mph. BMW overstates its speed.

[ur20v]

'you were caught speeding at 82 mph in a 70 zone, how do you plead'... 'well my speedo said I was only doing.... blah, blah, blah' LOL.

As dough boy said your speedo will be right at least once just like a stopped watch.

[GMT234]

So mine reads 167 when limiter comes in, does this mean it's 12mph out at this speed?

[ur20v]

^^^ each car is different, i.e. different tyres, different wear, different temp, different pressures. Ony way to check is via laser or calibrated GPS. Note 155mph is the German greed limit on their cars.

Does it mater unless you are racing... 155 or 179 mph, both mean probable jail time.