my 2008 335i speedo reads about 5% high accorging to GPS and radar. What is wrong and how can it be fixed?

It's supposed to read high. From a BMW service bulletin:

SUBJECT:
Maximum Permissible Speedometer Error


MODELS:
All


General Information:
A certain amount of "speedometer advance" is necessary to compensate for negative tolerances in tire diameter, electronic controls, and other factors. This advance reduces the risk of the speedometer displaying a speed that is less than the vehicle's actual speed.

The amount of speedometer advance can be calculated by inputting a frequency (using the DIS Tester, "Kombi Test Schedule") that corresponds to a given speed and noting the speed that is indicated by the speedometer. The maximum permitted speedometer advance is 10% of the actual (input) speed plus 2.4 mph.

Example:

Actual Speed = 50 mph

50 mph x 10% = 5 mph; 5 mph + 2.4 mph = 7.4 mph

Therefore, the permissible displayed speed is 50 to 57.4 mph.

(Note: The displayed speed must never be less than the actual speed).

No repairs should be attempted if the speedometer advance is within 10% + 2.4 mph.

NOTE: The amount of speedometer advance has no effect on recording of accumulated mileage in the odometer display. The odometer records total mileage digitally and does not incorporate any "advance" tolerances.

Search the forum for similar questions posts. This subject has been beaten to death with people on both sides of the argument.

That is not acceptable. No recent car has been that far off and I wont accept it from BMW. How is it adjusted???

That is not acceptable. No recent car has been that far off and I wont accept it from BMW. How is it adjusted???

:rolleyes

First German car ever, I assume? Is it me, or is the vast majority of E9X owners first time BMW buyers, like 99.9% +

It can't be adjusted. Complain loud enough, the dealer will bend the speedo needle slightly to "account" for the error.

That is not acceptable. No recent car has been that far off and I wont accept it from BMW. How is it adjusted???
You can sell your car and get one that is acceptable to you. There is nothing to say they have to give you an accurate speedometer, but there are many legally binding agreements that they have with European governments that say they are liable if they under report your speed, thus they err on the side of caution. Seriously, if you don't like it, get another car, and most probably that car will not be European because almost all European manufacturers do the same.

This error also affects cruise control. set it at 70 and you only go about 66.

Partial search is not showing how to fix it.

This error also affects cruise control. set it at 70 and you only go about 66.

Partial search is not showing how to fix it.
OMG, it is not an error, it is an intentional adjustment. And yes, it does affect cruise control, but not your odometer. As I said, for their own legal protection, BMW chose to over report your speed and anything up to 10% is acceptable to them no matter what you believe. Take it in and they will send you back home. And AFAIK, nothing can be done to change this behavior. Since you have GPS, why not calculate what % your car under reports and compensate accordingly. Surely that can't be so hard. Or you can keep complaining and pissing in the wind. Up to you.

:rolleyes

First German car ever, I assume? Is it me, or is the vast majority of E9X owners first time BMW buyers, like 99.9% +

It can't be adjusted. Complain loud enough, the dealer will bend the speedo needle slightly to "account" for the error.
lol, it seems many who join the forum are 1st time owner puzzled by their BMWs. Let's be nice to the noobs :stickoutt.
Btw, I doubt the dealer will do it (assuming you were being serious not sarcastic), since there is liability issues involved. But then if you have a good relationship with them, they may do stuff like that, but for a 1st time customer, esp. one who will go in and just bitch, they will just probably politely reject him.

not even my old F150 is off that far. I dont intend to rant to the dealer but doing math at 70 is not what I expect from a quality car. Everything else on the car, even the fenders are fit at much better than 10% accuracy. Imagine if the convertable top was 10% short?????

not even my old F150 is off that far. I dont intend to rant to the dealer but doing math at 70 is not what I expect from a quality car. Everything else on the car, even the fenders are fit at much better than 10% accuracy. Imagine if the convertable top was 10% short?????
What can I tell you. Again it is not a defect, it is intentional. Maybe you can complain to BMW corporate suits and they will listen and change their ways, until then, enjoy the car at whichever speed it tells you you are going.

I have no problem with the speedometer having a variance on my BMW, but FWIW the speedo on my C230 Coupe was accurate to within 1-2 MPH at 80MPH so it's not necessarily the same across every German car.

The "acceptable" variance that annoyed me with that car was where the dealer told me it was "acceptable" to burn 1qt of oil every ~1000 miles. Basically, if I had let the car go it's normal 10k maintenance interval, I would completely run dry on oil about half way there. They went as far as to replace the engine at 30k miles, but with the same result on the new engine. That's when they starting sticking to the "acceptable" variance story. :(

There is nothing to say they have to give you an accurate speedometer.

What else do they do that's not accurate? I guess they can make the entire care inaccurate if they choose to so.

What else do they do that's not accurate? I guess they can make the entire care inaccurate if they choose to so.
Inaccurate just like your typing. :stickoutt

It was a real pita when driving through speed trap alley in north central Florida on highway 301. I couldn’t figure out why people were passing me in this area of hostile speed cops while I had my cruise control set at the limit.
As to BMW’s fear of lawsuits I doubt that Honda adjust extra error into their speedos on cars sold in Germany and BMW make many accommodations to US preferences and laws in order to sell their cars here so it just does not make any sense.

In the era of ISO quality systems the answer that 10% is an acceptable variation is obsolete.

I guess I am off to see the dealer and see what happens now armed with the “official” illogic.

Thanks to everyone for the letting me know the issues even if they are all “wurst“. :D

It's supposed to read high. From a BMW service bulletin:


Thanks for posting that. I'm two weeks into ownership of my first BMW, and I too had noticed that I'll be driving at 65 mph, and cars were passing me. I turned on my Garmin GPS and saw that the car was reading a few MPH higher than the car.

My two recent Audi's were not so far off from the GPS, so I don't think this is generic to all German cars, unless it was a chance in the last 4 years or so.

Not a big deal, but I'm glad there is forum like this to get the real scoop.

My two recent Audi's were not so far off from the GPS, so I don't think this is generic to all German cars, unless it was a chance in the last 4 years or so.

FWIW, My 2007 Audi Q7 is off by 4 to 5 mph and our 328 is off by 5 to 6 mph. While I agree it is slightly annoying the byproduct has been that I haven't received a speeding ticket in 5 years. :redspot

I guess I am off to see the dealer and see what happens now armed with the “official” illogic.

Thanks to everyone for the letting me know the issues even if they are all “wurst“. :D

As a dealer tech, I am telling you that there is very little (if anything) they can do to fix it, but please keep us posted. I'm curious what they say.

JohnnyO, you're welcome. You guys own the cars, you have the right to know. They should put it in the owners manual.

Every BMW I have owned including an 85 E30, countless E30's, E36's and my E93 were always off. I corrected my M3 by running tires one size taller then stock. GPS shows it to be almost on the money.
I know that many of us E30 drivers just removed the cluster, popped the speedo out and bent the needle to compensate for BMW trying to protect us.

So for over 20 years they have been doing the same thing and I don't see that they will change.

Remember since BMW is a German company and they are never wrong, like Idrive in the first 7 series, there is no need to fix anything. Problem is they are not right either.

You should not have to guess at how fast you are going, you should know.

lol, it seems many who join the forum are 1st time owner puzzled by their BMWs. Let's be nice to the noobs :stickoutt.
Btw, I doubt the dealer will do it (assuming you were being serious not sarcastic), since there is liability issues involved. But then if you have a good relationship with them, they may do stuff like that, but for a 1st time customer, esp. one who will go in and just bitch, they will just probably politely reject him.

I've seen it done before for high maintenance customers. I've seen it done on a 5 series before so it's not unheard of.

Another thing you can try to "fix" the speedometer error is by going 1 aspect ratio higher on the tires. :dunno

I've seen it done before for high maintenance customers. I've seen it done on a 5 series before so it's not unheard of.

Another thing you can try to "fix" the speedometer error is by going 1 aspect ratio higher on the tires. :dunno
Wouldn't that mess up the odometer reading? I assume it has no effect on the other electromechanical system (ASC, DSC, EBD, ...).

Wouldn't that mess up the odometer reading? I assume it has no effect on the other electromechanical system (ASC, DSC, EBD, ...).

Sure, but people seem hell bent on wanting their speedometer to read exactly what the radar gun says when they get pulled over.

Now a days when I get pulled over by a LEO, and they ask me how fast I was going, I just tell them I don't know, since BMW speedometers can read up to 10% + 3mph faster than actual indicated speed. :D Except for that one time I got pulled over doing 75mph in a 35mph zone. No excuse there except for "I dunno officer, this car is so quiet and comfortable sometimes I forget how fast I was going."

And he let me off with a warning. :eyecrazy

Sure, but people seem hell bent on wanting their speedometer to read exactly what the radar gun says when they get pulled over.

Now a days when I get pulled over by a LEO, and they ask me how fast I was going, I just tell them I don't know, since BMW speedometers can read up to 10% + 3mph faster than actual indicated speed. :D Except for that one time I got pulled over doing 75mph in a 35mph zone. No excuse there except for "I dunno officer, this car is so quiet and comfortable sometimes I forget how fast I was going."

And he let me off with a warning. :eyecrazy
lol, I'll remember to use that excuse. I always say I am not sure when I get pulled over, no need to lie nor to admit guilt. He knows anyway, so leave it to the judge to decide, but I've been let off with warning before too, never used your excuse however :stickoutt.

Except for that one time I got pulled over doing 75mph in a 35mph zone. No excuse there except for "I dunno officer, this car is so quiet and comfortable sometimes I forget how fast I was going."

I had a 145 km/h in a 60 km/h zone when I was young and foolish.

I did not get off with a warning :-(

There have been several other threads on this... Yes, this does tick me off, yes, the EU punishes mfgrs for reading low but as I read in Roundel a couple of months ago BMW readings are "adjusted" to a higher percentage than the other EU mfgrs.

I've had 2 '97 BMW's (in addition to a couple other German cars) in the last year and none of them came close to my wife's '07 328 7% calculated error, checked using a Garmin w/ WAAS enabled. The other (German) cars were at MOST 2% off (which I can tolerate).

There have been several other threads on this... Yes, this does tick me off, yes, the EU punishes mfgrs for reading low but as I read in Roundel a couple of months ago BMW readings are "adjusted" to a higher percentage than the other EU mfgrs.

Maybe because BMW knows its customers are more likely to exceed the speed limit in its cars :devillook ;) ;).

If it bothers you that much, just get tires with a slightly larger diameter/circumference, and replace them whenever they wear slightly. Use the tirerack calculators to determine what will compensate.

A couple of comments.

First, it's not "variance," the way most people use the term. It's more like an "offset." In other words, what BMW did with the speedometer doesn't make it wander around -- vary -- in relation to the true speed to do the degree we're all complaining about. If it varied, it would be sometimes fast, sometime slow. But it's "always fast." So I don't think it's helpful to confuse the speedo problem with "tolerances," in the sense we all use the term (fender fit, machining in the engine, etc. etc.).

I don't like it either, but I can see the logic of it -- and BMW's logic is also used in other contexts. I spent 25 years as a professional timer (running races, not car races), and even longer than that as a professional course measurer (again, for running). And I put in time as a land surveyor, too. I won't bore you with the methods for measuring road courses that runners are going to compete on. But for the first decade or so that I was a course measurer, I measured courses as a surveyor would, taking care to make multiple measurements which of course varied from each other. I would take the average of all the measurements and mark the start and finish on that basis. This was the classic method, exactly as a surveyor would have done it.

Then, and I can't remember when this happened except that it was in the late seventies or early eighties, the sanctioning bodies who control courses, records, etc., decided on a BMW-like logic. What they said was, "courses are to be measured so as to have a high probability that they are NOT SHORTER THAN THE SPECIFIED DISTANCE." So, following the rules, we all duly added .1% (a tenth of a percent) to the measured distance. The idea was that since the permitted measurement tolerance by classic methods was set at +/- .08% that adding .1% would make it highly unlikely that the course was SHORT. The .1% extra is called the "Short Course Prevention Factor." I complained about this but to no avail. So, as I saw it, I then had to measure courses as precisely (and accurately) as possible and then make them long.

Before the whole world started measuring courses in this way, there were some potentially bad situations. In the eighties, Steve Jones ran what was then the world best for a marathon on one day, on a US course with the SCPF and then later in that day, in Europe, another runner ran a few seconds faster on a non-SCPF course. Jones lost his chance at the considerable money and other support that comes to a world-best runner, because of the SCPF. Over the marathon distance, the SCPF comes to about 138 feet, a significant difference if you're running.

Another timing issue in the running world is that for road race events, a runner's time is recorded to .01 second but the official time is always rounded up to the next higher full second, unless the fractional portion is .00. So 13:50.01 through 13:50.99 must be reported officially as 13:51 but 13:50.00 is reported as 13:50. In track it's different.

So, probably more than people wanted to know about measurement in another sport but my point is that however much we disagree with BMW's decision, its logic (make the speedometer read more than the actual speed so that ACTUAL IS NEVER MORE THAN THE INDICATED SPEED) is also used in other contexts.

Still, if we go back to the tight tolerances that BMW achieves everywhere else, it seems to me that they could easily design a speedometer with close tolerances, and then the must-not-read-less-than offset could be smaller.

Still, if we go back to the tight tolerances that BMW achieves everywhere else, it seems to me that they could easily design a speedometer with close tolerances, and then the must-not-read-less-than offset could be smaller.

A 10 PSI change in tire pressure could result in up to 2% difference in speedometer reading. Given the proclivity of U.S. car buyer's to NEVER check their tire pressure, I'm not sure how accurate BMW will have to build their speedometers and still have it never read slower than actual speed. :dunno

Now we know how the they post such good 0-60 times. lol

Now we know how the they post such good 0-60 times. lol
I am assuming you are joking, 1st because usually BMW posts very conservative 0-60 times (always bettered by at least 0.2-0.5 sec by 3rd parties), and second of all the car's speedometer is not used in the 0-60 measurement, usually professional equipment is used to automatically do the measurements.

It fits with the massive understeer from the staggered tires. BMW is deathly afraid someone might drive one like a performance car.

It fits with the massive understeer from the staggered tires. BMW is deathly afraid someone might drive one like a performance car.

Hello "darcydancer":

I must have missed something. What "fits"?

A couple of comments.

First, it's not "variance," the way most people use the term. It's more like an "offset." In other words, what BMW did with the speedometer doesn't make it wander aroundI see what you're saying, but it IS a variance, and it does wander. The accuracy of the speedometer varies from vehicle to vehicle, from one batch of speedometers to the next, etc. The tolerance specs describe the acceptable variance a specific built vehicle can have.

Just think of it as setting your watch ahead by 5 minutes...that's what I was always told.

Just think of it as setting your watch ahead by 5 minutes...that's what I was always told.

Hello "Chris17":

Actually, it should be a slope and intercept thing. Like Y = m *X + b. Otherwise the "zero" would have an offset.

You guys should join up with the VW Vortex speedometer bitchfest club. :D

Hello "darcydancer":

I must have missed something. What "fits"?
The speedometer irrational exuberance "fits" the "ultimate driving machine(not so much)" BMW zeitgeist. You have a car that isn't going as fast as you think it is, and has understeer to keep you safe.

lol, I'll remember to use that excuse. I always say I am not sure when I get pulled over, no need to lie nor to admit guilt. He knows anyway, so leave it to the judge to decide, but I've been let off with warning before too, never used your excuse however :stickoutt.

I've been surprised that I haven't gotten any speeding tickets yet... I think this migh be why... or they just don't want to pull me over because it's such a nice looking, brand new Montego blue BMW. Seriously, I entered a freeway and got up to just under 100 mph before I let off the gas in 3rd gear and there was a CHP car parked on the side of the freeway after the onramp and didn't move. I slowed down to 85, with the average flow of traffic (gotta love California) and tried not to stick out too much. The last time I got a speeding ticket, I got pulled over because I was clocked at 108 on the radar while accellerating on a freeway onramp... in my Maxima about 5 years ago. I'm much older and slower now.... or more concious of the speedo and it's off a bit and saving my butt.

I see what you're saying, but it IS a variance, and it does wander. The accuracy of the speedometer varies from vehicle to vehicle, from one batch of speedometers to the next, etc. The tolerance specs describe the acceptable variance a specific built vehicle can have.

Yes, you're right. I was unclear. What I meant was that the speedometer's going to vary because it's a measuring instrument in the real world, but that the area in which it's going to vary is offset from "true" by a fixed percentage that BMW sets for us. So we get offset + variation in such a way that the low speed tail of the variation never drops below the true speed.

In an earlier thread one of our tech members quoted the actual spec.

The speedometer irrational exuberance "fits" the "ultimate driving machine(not so much)" BMW zeitgeist. You have a car that isn't going as fast as you think it is, and has understeer to keep you safe.
The ultimate machine is driven by a majority who are not the "ultimate drivers", thus the extra safety features. It wouldn't be good for BMW image if noob BMW drivers kept crashing because they didn't know how to handle oversteer. Maybe they can make BMW driving schools mandatory to all buyers and then not compensate so much for inexperience! Far fetched, but I'd still signup.

[quote=mryakan;11500014]The ultimate machine is driven by a majority who are not the "ultimate drivers", thus the extra safety features. It wouldn't be good for BMW image if noob BMW drivers kept crashing because they didn't know how to handle oversteer.

I think you're right. I still prefer the Darwinistic approach of Porsche.

[quote=mryakan;11500014]The ultimate machine is driven by a majority who are not the "ultimate drivers", thus the extra safety features. It wouldn't be good for BMW image if noob BMW drivers kept crashing because they didn't know how to handle oversteer.

I think you're right. I still prefer the Darwinistic approach of Porsche.

Hello "darcydancer":

Darwin indeed! Low polar moment, lots of power, 911, guard rail, death ...

It does not get much better than that.

i really noticed the variance on a reason trip to Atlantic City. The main reason I hate the variance is that it advance the mileage on the car and therefore the car depreciates much quicker since it will always be off. It also makes an owner have to do more service if they are not aware of this variance, because a 60K mile checkout, should actually be done at like 67,000 miles. Thats a big difference.

i really noticed the variance on a reason trip to Atlantic City. The main reason I hate the variance is that it advance the mileage on the car and therefore the car depreciates much quicker since it will always be off. It also makes an owner have to do more service if they are not aware of this variance, because a 60K mile checkout, should actually be done at like 67,000 miles. Thats a big difference.
It DOES NOT affect the odometer, just the speedometer.

I'm surprised the dealer cannot adjust the speedo with the OBD tool. My Jeep's speedometer can be adjusted to accomodate different tire sizes. They can eithe select one of the pre-determined settings for different tire sizes, or just plug in the rotations per mile. That's how I got my speedo accurate when I went from 30" to 31" tires (it's a Jeep that sees the trail, so you want TALLER tires, not lower ;-).

Cars haven't used speedo gears for years. So the advantage is a reduction in hard parts because of programmability. (I'm still searching for the right gear combo in my 68.) so why not allow techs to adjust the speedo. I can understand why they don't WANT their techs to do it, but not being able to do it? Seems odd. Especially on cars where aftermarket rims are so commonplace.

The ultimate machine is driven by a majority who are not the "ultimate drivers", thus the extra safety features. It wouldn't be good for BMW image if noob BMW drivers kept crashing because they didn't know how to handle oversteer
so I guess honda owners are better drivers than BMW drivers since the wife's Odssey van speedo is correct.

It DOES NOT affect the odometer, just the speedometer.
the cruise control as well

[quote=darcydancer;11504394]

Hello "darcydancer":

Darwin indeed! Low polar moment, lots of power, 911, guard rail, death ...

It does not get much better than that.
If I were you, I'd stay away from them until you learn how to drive. Even the post 04 Carreras are not for poseurs.

I have decided that when asked about the length of my private member I will overestimate by .01% from now on

You guys should join up with the VW Vortex speedometer bitchfest club. :D
Same thing there?

so I guess honda owners are better drivers than BMW drivers since the wife's Odssey van speedo is correct.
Last I checked no one tried to race an Odessey, but I could be wrong :D.

you got to be kidding, people race sailboats

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That's funny!

you got to be kidding, people race sailboats
they race dogs too, whats your point? :confused

Must be rough having to live life comfortably enough to have a BMW, while still stressing about such serious things as speedometer offset.

I don't get this! My '04 Acura TL was dead on the money no matter what the tire wear was and a whole bunch of other factors. The speedo would recalibrate itself as necessary. I expect to see some speedo error but my brand new 328 is way too high. i'll check the odo though. I know exactly how far it is from my office to home (9.6km) and I'll see just how far off the odo is, or isn't. In any case, in this day and age, no matter what BMW's past history on speedo error is, this is just wrong. If Acura can get it right... so can BMW. There's just no acceptable excuse.

I don't get this! My '04 Acura TL was dead on the money no matter what the tire wear was and a whole bunch of other factors. The speedo would recalibrate itself as necessary. I expect to see some speedo error but my brand new 328 is way too high. i'll check the odo though. I know exactly how far it is from my office to home (9.6km) and I'll see just how far off the odo is, or isn't. In any case, in this day and age, no matter what BMW's past history on speedo error is, this is just wrong. If Acura can get it right... so can BMW. There's just no acceptable excuse.
huh :confused, how would the speedo know how to recalibrate itself. Short of using a GPS or radar to detect real speed (and even that is prone to error), I can't see how the car can tell what the actual speed is. The manufacturers set the wheel rotation to speed factor based on recommended OEM tire/wheel sizes, that is why when you go with non-OEM wheels/tires, your speedo will most probably be incorrect one way or another.

P.S. Not sure how you can call it an error, when it is intentionally done by BMW, maybe error in judgment! :rolleyes

Search the forum for similar questions posts. This subject has been beaten to death with people on both sides of the argument.


:deadhorse::deadhorse::deadhorse:


thank you

huh how would the speedo know how to recalibrate itself. Short of using a GPS or radar to detect real speed (and even that is prone to error), I can't see how the car can tell what the actual speed is. The manufacturers set the wheel rotation to speed factor based on recommended OEM tire/wheel sizes, that is why when you go with non-OEM wheels/tires, your speedo will most probably be incorrect one way or another.

P.S. Not sure how you can call it an error, when it is intentionally done by BMW, maybe error in judgment!

It was GPS calibrated in the TL. I used the TL's onboard diagnostics, a magellan handheld GPS and a MIO pocket-pc based GPS and they all indicated the same speed while I had the cruise control on a flat part of the 401 east of Kingston. Works just fine. My 328 was wrong though. and yes... it's an ERROR ! error in the sense that the indicated speed is nowhere near the real speed. Intentional or not, the speedo is in error. If I design a piece of software with an intentional error and then claim "it's by design", it's still an error. BMW's speedo is in ERROR. I do understand their logic and it does make sense but it's still in error nonetheless.

Alright, we all said our peace, let's wrap up this thread. Any reason to keep it open!

Except for that one time I got pulled over doing 75mph in a 35mph zone. No excuse there except for "I dunno officer, this car is so quiet and comfortable sometimes I forget how fast I was going."

I had a 145 km/h in a 60 km/h zone when I was young and foolish.

I did not get off with a warning :-(

Try 113 in a 50...in MPH. Snip, there goes the license, after 5 yrs of litigation. God Bless the USA.