Difference between actual speedo reading and digital reading?

[MikeeM3]

Hi guys,

I notice a big difference between the acutal speedometer reading with the needle and the digital one is this normal??

When im driving 60mph i have a 2mph difference and i did some high speed run last night on a freeway in mexico and the difference was even bigger with a 15mph difference from both speed reading... should i assume that the digital one is more accurate??

Do some of you guys have the same issue on your cars?

[Sephiroth]

Yup same on my car, although i haven't verified what happens above triple digits. I even notice a discrepancy going up/down hills at highway speeds.

[DSilk]

The needle on the gauge always seems to read a couple of mph faster than actual speed, and this has been true of every BMW (and Audi) I've owned. The digital readout is more accurate.

[JDM_CL9]

Haven't done it yet but isn't there some coding you can do to display actual vehicle speed?

[jdamore]

You'll find that the analog speedo is about 3-4% faster than actual speed. The higher the speed the more mph difference.

You thought "80mph feels smooth!" because you're 75 ya dummy lol

[jdamore]

Originally Posted by JDM_CL9

Haven't done it yet but isn't there some coding you can do to display actual vehicle speed?

Only for the digital. Not for analog (unless someone figured it out recently)

[MikeeM3]

Thanks guys !!! I was all excited that my needle was showing 200 but my digital was only at 184 !!

[bigwave]

New guy here. Is there a Digital Speed display setting I am missing? 2008 M3 Cpe with out Premium package.

Thanks

[JDM_CL9]

Originally Posted by bigwave

New guy here. Is there a Digital Speed display setting I am missing? 2008 M3 Cpe with out Premium package.

Thanks

On your signal stalk, do you have a BC button?

[bigwave]

I do

[bigwave]

found it. Learn something new with this car everyday

[jphughan]

Analog speedos read fast because it's illegal for them to read even 1% slow, and since automakers aren't willing to calibrate speedos for consumer cars individually the way they do for law enforcement vehicles, they just play it safe. That's also helpful in light of the aftermarket tendency to fit larger diameter wheels to cars, which causes you to travel faster at a given engine speed and gear compared to smaller wheels.

The digital speedo is enabled by default on the M3 (can be coded on for series cars) but if I remember correctly, the default mode is to make it match the analog speedo. There's a separate coding option that determines whether it displays the true speed or the speed that matches the analog speedo.

[Beemdog]

Should also be noted that odometers are required to have a certain degree of accuracy due to things like warranties based on mileage, even if speedos are not. Most cars seem to have the speedometer readings around 3-5% high, with motorcycle speedometers even worse at 7% high! A good portable GPS unit with a speed indicator will give an idea of how far off your speedo really is...

[M3 Number 86]

my Aim Solo DL GPS speed says there is about a 10 mph difference when going around the Nascar banking.

Speedo shows 135mph, datalogger says 125mph. Damn I thought I was going fast.

[nickl630]

Yes this is normal and can be corrected with coding, look in the coding section of this forum or search for "m3 digital speedometer correction"

As others have said its illegal in the EU (and probably here) to have the speedo read even 1% lower than it should. It probably helps you get less tickets too as your going slower than you think lol.

[krx927]

Originally Posted by nickl630

Yes this is normal and can be corrected with coding, look in the coding section of this forum or search for "m3 digital speedometer correction"

1+

[brownb_2]

so is the digital display of speed a GPS indication?