[srd5948]

Hey guys, I am new to this forum, I have 2011 BMW 335i sedan.
I have a question with respect to the speed meter gauge. How do I know, if the speed shown in the gauge is the correct since when I am travelling my GPS (Tomtom) shows 77mph but my car gauge shows 80mph. I am confused.

Has anyone noticed this or this just a case with me?

Please advice.

[tbracing]

The speedo on our cars for some reason are set like this from factory.

[username604]

most cars are like this. most people agree our cars read 3 mph high all over the speedometer. something to do with liability if the car reads too low.

[ChuckBMW3]

Originally Posted by srd5948

Hey guys, I am new to this forum, I have 2011 BMW 335i sedan.
I have a question with respect to the speed meter gauge. How do I know, if the speed shown in the gauge is the correct since when I am travelling my GPS (Tomtom) shows 77mph but my car gauge shows 80mph. I am confused.

Has anyone noticed this or this just a case with me?

Please advice.

My speedometer reads 3 MPH too fast as well

[jgrasty]

GPS speed is trustworthy. You'll find BMW speedometers always read high. Changing tire diameter due to tire wear also will influence the speed displayed.

[srd5948]

Thank you guys for the response..

[CirrusSR22]

All BMWs have done this going back decades.

[ctuna]

I think the cars have to read low in Germany or Europe, its the law.
The guys on the coding board have found the hidden key to allow
the true speed to be displayed digitally by defeating some correction
factor and enabling a digital speed function in the programming.
I wonder how much a GPS is off if your going up and down Hills.

[srd5948]

Can it be fixed by any means?

[MotorenWerkeN52]

I dont think this is just a german thing... i have noticed this on almost every car i have driven.

[jphughan]

Speedometers tend to read about 5-7% fast because it's illegal in many (all?) countries for them to read even 1% slow, so the manufacturers err on the safe side. Yes, through coding there is a way to get the computer to display a digital speedometer in your cluster WITHOUT the "safety" adjustment factor added. It might still not match GPS because as others have mentioned, inaccuracies in the electronics and factors like running non-standard tire sizes or even different levels of treadwear can all affect accuracy, but the "true" speedo should be substantially closer to GPS.

[Tom K.]

Although the speedometer should not read low, the error is not consistent. The 5 Bimmers I've owned have ranged from about 5% high to accurate within 1%.

But they are much better than the old magnetic instruments which were often off by 15% or more.

Tom

[SilverII]

i use the mph indicator in my 9500ix. however, it goes up to 99mph only.

[mike3000fl]

if you access the hidden menu you can see the true car speed. as others have suggested the car adds about 3mph.

the hidden menu speed matches my GPS. my speedo does not. i have tested this with cruise control on long drives where i got bored enough to wonder about this.

[bimmerjph]

Car makers get enormous fines if their speedos read slow, so they make the 2-5mph fast as a safe guard.

[mike3000fl]

heres a thought that crossed my mind.

if the speedo says im going faster than what i really am, then i am racking up miles faster than i really am.

3mph off driving an average of 30mph is 10%
3mph off driving an average of 60mph is 5%

If i pay for a 100,000 warranty/maintenance plan. am i getting fucked out of 5 to 10% of it because the car says I am at 100,000miles when really I am at 90,000?

not a big deal unless something like a motor blows at 102,000miles.

[wdlfbio]

I coded my 2012 to show VO digitally, then I coded it to show the accurate speed. My digital VO speed shows 3 mph below the analog speedometer starting around 50+. At 108 mph on the speedo, the digital is 100.

[mike3000fl]

Originally Posted by wdlfbio

I coded my 2012 to show VO digitally, then I coded it to show the accurate speed. My digital VO speed shows 3 mph below the analog speedometer starting around 50+. At 108 mph on the speedo, the digital is 100.

so with that, at 108,000 miles on odometer, you will have only really traveled 100,000 mi

when your odo rolls over 100,000 your car has only gone about 93,000

we are losing part of the warranty.

[iBeech]

Originally Posted by mike3000fl

heres a thought that crossed my mind.

if the speedo says im going faster than what i really am, then i am racking up miles faster than i really am.

3mph off driving an average of 30mph is 10%
3mph off driving an average of 60mph is 5%

If i pay for a 100,000 warranty/maintenance plan. am i getting fucked out of 5 to 10% of it because the car says I am at 100,000miles when really I am at 90,000?

not a big deal unless something like a motor blows at 102,000miles.

No, because the mileage goes off the actual speed your traveling at

[tbracing]

Originally Posted by SilverII

i use the mph indicator in my 9500ix. however, it goes up to 99mph only.

How do you like your 9500ix? Do you get alerts fast enough to get down to a "lawful" speed, considering the difference in spedo reading?

[jphughan]

Originally Posted by mike3000fl

heres a thought that crossed my mind.

if the speedo says im going faster than what i really am, then i am racking up miles faster than i really am.

3mph off driving an average of 30mph is 10%
3mph off driving an average of 60mph is 5%

If i pay for a 100,000 warranty/maintenance plan. am i getting fucked out of 5 to 10% of it because the car says I am at 100,000miles when really I am at 90,000?

not a big deal unless something like a motor blows at 102,000miles.

No, the car uses its true speedometer reading to calculate mileage.

[EQUANT]

You can code the speedo deviation out, so you'll get the real speed on your digital speedo reading, in the BC.