After taking delivery of a new E92 325i coupe a week ago, I am a bit
disappointed with the fact that the speedometer indicates 100 kph
while the car is actually only doing 95 kph (extensive test on flat
motorway using tom tom 910 GPS).

Is this sort of error considered normal or acceptable?

Can anything be done about it?

The car is absolutely brilliant in all other respects.

"Bob Morrison" <rmorrison1nospam@bigpond.com> wrote
> After taking delivery of a new E92 325i coupe a week ago, I am a bit
> disappointed with the fact that the speedometer indicates 100 kph
> while the car is actually only doing 95 kph (extensive test on flat
> motorway using tom tom 910 GPS).
>
> Is this sort of error considered normal or acceptable?

Typical.

> Can anything be done about it?

No, not really. You *can* get the actual speed from the computer
if you fiddle around.
The reason it's fast is a combination of EU and US requirements -
it must never read low, essentially.

> The car is absolutely brilliant in all other respects.

FloydR

In article <13jd9jmh96cc528@corp.supernews.com>,
Floyd Rogers <fbloogyuds@hotmail.com> wrote:
> The reason it's fast is a combination of EU and US requirements -
> it must never read low, essentially.

Nothing to stop it being accurate - or the over-reading error being tiny.

There are advantages to a maker to deliberately have the device over-read
by such a large margin. Makes the car appear faster than it is. If it
extends to the odometer a milage based warranty runs out sooner and MPG
appears better too.

--
*Organized Crime Is Alive And Well; It's Called Auto Insurance.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote
> If it
> extends to the odometer

It doesn't.

Pete

On 11 Nov, 05:38, Bob Morrison <rmorrison1nos...@bigpond.com> wrote:
> After taking delivery of a new E92 325i coupe a week ago, I am a bit
> disappointed with the fact that the speedometer indicates 100 kph
> while the car is actually only doing 95 kph (extensive test on flat
> motorway using tom tom 910 GPS).
>
> Is this sort of error considered normal or acceptable?
>
> Can anything be done about it?
>
> The car is absolutely brilliant in all other respects.

You used to be able to update the software/firmware speedo calibration
factor but I don't know if that's still possible.

"Bob Morrison" <rmorrison1nospam@bigpond.com> wrote in message
news:8u4dj3d2ko57ctnuaud79a8g1muf4fd30e@4ax.com...
> After taking delivery of a new E92 325i coupe a week ago, I am a bit
> disappointed with the fact that the speedometer indicates 100 kph
> while the car is actually only doing 95 kph (extensive test on flat
> motorway using tom tom 910 GPS).
>
> Is this sort of error considered normal or acceptable?
>
> Can anything be done about it?
>
> The car is absolutely brilliant in all other respects.

Perfectly normal. You should be able to get a more accurate reading by
doing a reset of the OBC if necessary.

Years ago, Road & Track magazine routinely included speedometer error (at 30
and 60mph, IIRC) in their road test info, and Motorcycle Consumer News still
measures it @60 mph for tested motorcycles. Worst error I personally recall
was my 1976 R75/6 cycle which read 125 at its top speed of 102.

Tom K.

It is normal for the speedo to read faster than you are actually travelling
with all car manufacturers.

The specification varies between manufacturers, but as a general rough
estimate, I would expect to see around a 10% difference.


"Bob Morrison" <rmorrison1nospam@bigpond.com> wrote in message
news:8u4dj3d2ko57ctnuaud79a8g1muf4fd30e@4ax.com...
> After taking delivery of a new E92 325i coupe a week ago, I am a bit
> disappointed with the fact that the speedometer indicates 100 kph
> while the car is actually only doing 95 kph (extensive test on flat
> motorway using tom tom 910 GPS).
>
> Is this sort of error considered normal or acceptable?
>
> Can anything be done about it?
>
> The car is absolutely brilliant in all other respects.

Sorry forgot to mention, this is done firstly to protect the manufacturer in
the event of legal cases, but also to accommodate for differences in
driveline tolerances. For example, a brand new tyre will have a larger
diameter that a worn out tyre.


"Ali" <me@privacy.net> wrote in message
news:KVHZi.21605$6v.19273@newsfe2-gui.ntli.net...
> It is normal for the speedo to read faster than you are actually
> travelling with all car manufacturers.
>
> The specification varies between manufacturers, but as a general rough
> estimate, I would expect to see around a 10% difference.

"Bob Morrison" wrote
> Can anything be done about it?

Short of getting slightly larger tires, not really.

Generally, speedos are allowed to read up to 10% high.

Pete

It is both normal and acceptable.

My car is a '94 E36 that came with 225/55x15s. I've changed the tire package
on my car to a 225/45x17, and when my speedo reads 80 on a measured mile,
the stop watch is off by just fractions of a second -- meaning my actual
speed is about 79. The 17s on my car are just a tad larger than the 15s that
came on it, which has the effect of slowing the speedo. As a matter of
design, the speedo reads faster than actual speed so that when you set your
speed in compliance with the roadside singage, you do not run afoul of the
law.

If your car is really doing 95kph at an indicated 100kph, then your actual
speed and indicated speed is pretty much the same as mine, and I had to
change my tire package to get where I am.




"Bob Morrison" <rmorrison1nospam@bigpond.com> wrote in message
news:8u4dj3d2ko57ctnuaud79a8g1muf4fd30e@4ax.com...
> After taking delivery of a new E92 325i coupe a week ago, I am a bit
> disappointed with the fact that the speedometer indicates 100 kph
> while the car is actually only doing 95 kph (extensive test on flat
> motorway using tom tom 910 GPS).
>
> Is this sort of error considered normal or acceptable?
>
> Can anything be done about it?
>
> The car is absolutely brilliant in all other respects.