[lordbmw]

When my speedometer reads 75 mph my phone nav app says 72 or 71mph.

I believe that my phone nav app is correct (apple map actually)

I understand that's the way BMWs are from the factory.

Is there a way to "fix" it ?

[floydarogers]

Originally Posted by lordbmw

When my speedometer reads 75 mph my phone nav app says 72 or 71mph.

I believe that my phone nav app is correct (apple map actually)

I understand that's the way BMWs are from the factory.

Is there a way to "fix" it ?

There is a way to display the correct value as digital info, but no way to change the speedo itself (AFAIK).

This is standard, because of laws/regs in the US/CA/EU.
There are quite a few threads on this, at least one of which mentions the coding. Use the Search function (or Google.)

[slupie]

Originally Posted by lordbmw

When my speedometer reads 75 mph my phone nav app says 72 or 71mph.

I believe that my phone nav app is correct (apple map actually)

I understand that's the way BMWs are from the factory.

Is there a way to "fix" it ?

Search, it has been covered about million+ times

[TailgatingBMW]

This is a normal "safety" feature so that you don't get a ticket if speedo shows a little over the speed limit. I do believe you can get your car coded so it shows the actual speed (at your own risk).

[Socket]

Normal
Can be coded out to show true speed or if you have NBT then there is an option to show true speed under vehicle settings

[Mr. Tasty]

Just put larger diameter tires in the rear. Problem fixed.

[floydarogers]

Originally Posted by Mr. Tasty

Just put larger diameter tires in the rear. Problem fixed.

Actually, not! The speedo is driven off the ABS sensors, not a cable driven in the transmission. Get into the modern world!

[John 070]

Originally Posted by TailgatingBMW

This is a normal "safety" feature so that you don't get a ticket if speedo shows a little over the speed limit. I do believe you can get your car coded so it shows the actual speed (at your own risk).

I too was surprised back in 07, kinda contrary to this notion that Germans are precise. Reminds me of people who set their watch ahead by 17 min. so they're not late. Kind of nonsense, but who are we peasants to say

[TailgatingBMW]

Originally Posted by John 070

I too was surprised back in 07, kinda contrary to this notion that Germans are precise. Reminds me of people who set their watch ahead by 17 min. so they're not late. Kind of nonsense, but who are we peasants to say

In some parts of Europe which use speed cameras, not cops who patrol around, you can get dicked over for even the slightest amount of speeding (1 km/h over). That's why basically all cars (in Europe at least) have this feature.

[d1saster]

Originally Posted by floydarogers

There is a way to display the correct value as digital info, but no way to change the speedo itself (AFAIK).

I coded my analog speedometer to show just 1 mph off at 80. It has been covered in the coding subforum.

[feuer]

Is almost 2017.

[Wilt]

Originally Posted by floydarogers

There is a way to display the correct value as digital info, but no way to change the speedo itself (AFAIK).

This is standard, because of laws/regs in the US/CA/EU.
There are quite a few threads on this, at least one of which mentions the coding. Use the Search function (or Google.)

I simply do not believe 'it is law' that the E90 have such an optimistic speedometer.
My E46 speedo was pretty accurate, as verified by Garmin GPS speed reading as recent as 2010...and that GPS unit got moved to my E90.
An F22 service loaner which I drove less than a month ago agreed with my newest Garmin GPS (which I also use in my E90 whose analog speedo still reads 4% optimistic, and the same GPS which I had transferred to the F22 for the day).

Yes, there is apparently some law in Germany about speedometers not reading pessimistic...but the experiences I have had with E46 and F22 with the same GPS units as used in the E90 don't seem to make it a requirement that BMWs ALL are 4-5% optimistic like the E9n!

I have used Carly to activate my digital speed display on the dash, but unfortunately Carly does not code corrections of the analog display (or the cruise control display)

[floydarogers]

Originally Posted by Wilt

I simply do not believe 'it is law' that the E90 have such an optimistic speedometer.
M...

I (and others) have previously posted the law, or links to the regulations. Sorry, but you need to actually seek out those posts before making such statements.

The "law" allows for ridiculously poor accuracy (your "optimistic" characterization). It seems that some cars are just worse than others: my E90 speedo is about 3% over at an indicated 80 mph, so your 4% or whatever is beyond that. Too bad. I feel for you but can't reach you to pat you on the back in sorrow.

[Beekster]

It is even worse with the E87 series

[Greyfox]

Okay, the funniest thread I've read here is "put a bigger tire on". Really?

So, my car chrono's that cruise control set at 77 the car is actually doing 75... what is the big deal? And don't know about ya'lls speedo but mine only has 5mph incremental marks and depending on the angle you view the thing, your observation could be off by mile or two an hour.

And it's very easy to check... find some where there is a measured mile, set cruise before first marker, when you hit the marker start a stopwatch, stop the stopwatch at the mile marker.... 3600 divided by seconds to cover mile = mph car is doing.

ie... 3600 / 48sec = 75mph

[Mr. Tasty]

Originally Posted by floydarogers

Actually, not! The speedo is driven off the ABS sensors, not a cable driven in the transmission. Get into the modern world!

can't tell if sarcastic or serious haha.

[Mr. Tasty]

Originally Posted by Greyfox

Okay, the funniest thread I've read here is "put a bigger tire on". Really?

It isn't incorrect though. The larger the overall diameter of the tire, the further distance traveled per revolution. Pretty simple stuff.

[Wilt]

Originally Posted by floydarogers

I (and others) have previously posted the law, or links to the regulations. Sorry, but you need to actually seek out those posts before making such statements.

The "law" allows for ridiculously poor accuracy (your "optimistic" characterization). It seems that some cars are just worse than others: my E90 speedo is about 3% over at an indicated 80 mph, so your 4% or whatever is beyond that. Too bad. I feel for you but can't reach you to pat you on the back in sorrow.

My point, as borne out by the fact that the E46 and F22 with stock tires fitted from the factory, both measure vs. external GPS as ACCURATE, is that the German law apparently does not mandate 4% error...otherwise the E46 and F22 should both be as bad as the E90! Yet all three cars are fully compliant with German law, in spite of two having accurate speedometers and one has a noticeable error.

[floydarogers]

Originally Posted by Wilt

My point, as borne out by the fact that the E46 and F22 with stock tires fitted from the factory, both measure vs. external GPS as ACCURATE, is that the German law apparently does not mandate 4% error...otherwise the E46 and F22 should both be as bad as the E90! Yet all three cars are fully compliant with German law, in spite of two having accurate speedometers and one has a noticeable error.

My E46 was 2 mph high at 70 mph. My wife's 328d is 2-3 mph off at 70. My anecdotal data negates yours.

[Greyfox]

Originally Posted by Mr. Tasty

It isn't incorrect though. The larger the overall diameter of the tire, the further distance traveled per revolution. Pretty simple stuff.

Yes, bigger tires cause you to travel further per revolution.

But that is not where the controls on the E9x are messed up since you can code a visual display that gives your true speed. You have to recode the computer to not add +3% to true speed for the mph indicator in the speedometer.

[Mr. Tasty]

Originally Posted by Greyfox

Yes, bigger tires cause you to travel further per revolution.

But that is not where the controls on the E9x are messed up since you can code a visual display that gives your true speed. You have to recode the computer to not add +3% to true speed for the mph indicator in the speedometer.

weird, my indicated 80 mph analog speedometer is a true 80 mph by gps.

[natedog7700]

If i had a dollar for every time this question was asked.... Its intentional OP. Its a percentage, not a set amount. You can get the center display to indicate GPS based speed like shown in this video.