[Charter23]

So I noticed today that my speed on the heads up display and what was showing on the Waze app were out of sync. I engaged cruise control and my heads up was consistently 3mph higher than the app. Later I downloaded a speedometer app, performed the same test. Heads up said 83mph, app said 80mph.

I suspect most of us here will say trust BMW not an app, but a google search brought me to a GMC forum which said trust the app and not GMC, lol!

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[TZ]

I have the exact same thing. BWM displays slightly higher speed than actual on purpose to guarantee the compliance of speed limits.

[ezaircon4jc]

Originally Posted by Charter23

So I noticed today that my speed on the heads up display and what was showing on the Waze app were out of sync. I engaged cruise control and my heads up was consistently 3mph higher than the app. Later I downloaded a speedometer app, performed the same test. Heads up said 83mph, app said 80mph.

I suspect most of us here will say trust BMW not an app, but a google search brought me to a GMC forum which said trust the app and not GMC, lol!

:

Originally Posted by TZ

I have the exact same thing. BWM displays slightly higher speed than actual on purpose to guarantee the compliance of speed limits.

I've read all over the interweb that the BMW's speedo reads 3mph over. I wouldn't trust a cell tower based readout.

[Charter23]

Originally Posted by ezaircon4jc

I've read all over the interweb that the BMW's speedo reads 3mph over. I wouldn't trust a cell tower based readout.

Agreed but they are not mutually exclusive. If the general consensus is that BMW really is 3mph over, which I found consistently 3mph faster than my phone, then the argument could be made to trust the mobile GPS.

Regardless, is there a fix for this? Overestimating speed is like my wife setting her cars clock 5 min fast so she is on time.

It makes no sense and triggers me!

[Surly73]

The speedo reads high - most brands probably are and BMW's have been known to be for decades. Porsche too. This is so that no one can sue the manufacturer when they get a speeding ticket.

My E90 could be coded to show a "true speed" indicator digitally on the cluster. On my 1998 E39 I had to use the OBC average speed indicator - reset it and the first speed that pops up was "true".

Note that the odometer is correct. If you find a "measured mile" or "measured kilometer" on a local highway, you'll find your odometer counts the distance correctly but the speedo reads low if you add a stopwatch into the experiment.

[ezaircon4jc]

Originally Posted by Surly73

The speedo reads high - most brands probably are and BMW's have been known to be for decades. Porsche too. This is so that no one can sue the manufacturer when they get a speeding ticket.

My E90 could be coded to show a "true speed" indicator digitally on the cluster. On my 1998 E39 I had to use the OBC average speed indicator - reset it and the first speed that pops up was "true".

Note that the odometer is correct. If you find a "measured mile" or "measured kilometer" on a local highway, you'll find your odometer counts the distance correctly but the speedo reads low if you add a stopwatch into the experiment.

That can be coded but it apparently doesn't work. At least it doesn't work on either of our 535i's.

[Surly73]

Originally Posted by ezaircon4jc

That can be coded but it apparently doesn't work. At least it doesn't work on either of our 535i's.

It's not one of the things I even tried to code so I can't report any success...

[snj1013]

BMW's are known for being optimistic. Your app is probably correct.