BA Falcon speedo anomaly
Kev
with the GPS on my phone(uses Garmin City Navigator, IGo8 or Sigic
McGuider software)
With the speedo reading 105kph the GPS tells me I'm only doing 100
same at 80, I have to show 85 on the speedo to be doing 80
So the speedo is reading 5kph fast
now the interesting thing
when I check the speed reading on the car's trip computer it's reading
exactly the same as the GPS while the speedo is reading 5kph higher
anyone know where the trip computer gets the speed reading from?
Kev
Scotty
"Kev" <kev...@optunet.com.au> wrote in message news:497a7ee9$0$3321$afc3...@news.optusnet.com.au...
: Was driving home this morning and decided to check the speedo accuracy
Speedo installed by a manufacturer that doesnt wish to get sued by having a speedo "Out". A mates
brand new Navara is 10% out.
Noddy
> anyone know where the trip computer gets the speed reading from?
They get it from the wheel speed sensor the same as the speedo. The speedo
is just happy like most of them seem to be.
Just out of curiosity Kev, what phone are you running your satnav stuff on?
I've got Garmin working on an N95 and it's fucking hopeless in my opinion.
It *looks* pretty but it's not a patch on the Igo8 software running on the
satnav unit in my ute.
Any clues about Igo8 on a Nokia?
--
Regards,
Noddy.
F Murtz
speedo works with a slipping arangement
James
Interesting that. On the VX commy we have it's a piece of piss to calibrate
the speedo + / - 20km/h @ 100km/h. Will have to check and see if it changes
the trip meter as well. If it did it would make it very easy to make the
odometer tick over 20% slower. That's probably why the calculation is
different for the trip meter / odometer and the speedo as you mentioned.
James
D Walford
That appears to be very common and John H has mentioned doing the same
test with the same results.
AFAIK they get their reading from the same place but the variation is
due to the way they are calibrated.
Daryl
John_H
Same place as the speedo.
The standard arrangement, which the BA will almost certainly have, is
a pulse generator driven from the transmission mainshaft -- the same
place as the old cable operated speedos used to be driven from.
The speedometer itself is what produces produces the difference in
readings. The ADR's relating to speedometers actually specify two
different levels of accuracy, one for the odometer and a lesser degree
of accuracy for the speed reading, which some manufacturers choose to
exploit (for reasons only known to themselves).
You can check the base accuracy (as I've now done on a number of
occasions) by comparing the GPS's trip computer with the the odometer.
Yours will almost certainly be as near as damnit to spot on (same as
the car's trip computer) as any of those I've checked have been
(provided of course the correct sized tyres are fitted).
There's absolutely no reason why the speedo couldn't have been
calibrated to the same accuracy as the odometer (and the trip
computer) had the manufacturer chosen to do so.
Why some manufacturers don't, while others do, is anyone's guess. :)
--
John H
Kev
Using an HTC Tytn II
If your Nokia runs either Win Mobile or Simbian then most of the GPS
software for mobiles will have a version
head over to www.austech.info and www.ppcwarez.org
and go through the GPS forums
you might find that you can get Tom Tom or the Sygic McGuider software
running on it also
while you're there check out the other software apps available
Kev
Scotty
"John_H" <john...@inbox.com> wrote in message news:912mn4553015g9c9n...@4ax.com...
Ive a Garmin I use in the Hilux. Now the correct tyres have been fitted the speedo and Garmin are
spot on together. I did a trip from Brisbanes North Side to Tweed Heads and it worked out that the
speedo read 0.05% lower than the GPS. The speedo reads exactly what the GPS says at the time (Its
an needle so difficult to read the exact reading) but close as it needs to be. I do notice that
when on the hiway that I seem to travel a little faster than most new cars, assuming that they are
traveling at what they assume is 100kph. Its there that I found me mates speedo was 10% out, he
called me and told me I was a lead foot as I had over taken him when I was doing 110 on my speedo
and his was also sayign 110. I gave him the Garmin and he was convinced that it was wrong until he
bought a different brand and it was the same as the Garmin, his brand new Navara was 10% out.
(Reading under). Aparently he has clocked the same reading with another freind of his with the same
NAvara and he too was under by the same amount. Would Nissan do this to compensate for the obvious
next move by the owner to fit larger tyres??
John_H
>
>Ive a Garmin I use in the Hilux. Now the correct tyres have been fitted the speedo and Garmin are
>spot on together. I did a trip from Brisbanes North Side to Tweed Heads and it worked out that the
>speedo read 0.05% lower than the GPS. The speedo reads exactly what the GPS says at the time (Its
>an needle so difficult to read the exact reading) but close as it needs to be. I do notice that
>when on the hiway that I seem to travel a little faster than most new cars, assuming that they are
>traveling at what they assume is 100kph. Its there that I found me mates speedo was 10% out, he
>called me and told me I was a lead foot as I had over taken him when I was doing 110 on my speedo
>and his was also sayign 110. I gave him the Garmin and he was convinced that it was wrong until he
>bought a different brand and it was the same as the Garmin, his brand new Navara was 10% out.
>(Reading under). Aparently he has clocked the same reading with another freind of his with the same
>NAvara and he too was under by the same amount. Would Nissan do this to compensate for the obvious
>next move by the owner to fit larger tyres??
Very unlikely they'd do it for that reason as the odometer, which is
very likely to be accurate, would also be affected (as would the trip
computer if it's got one). You could check the odometer against the
GPS to determine if this is the case (the greater the distance the
better the accuracy).
AFAIK ADR's currently specify an odometer accuracy of +4%, -0, whereas
the speedo is specified as +10 kph, -0 at 100 kph (ie up to 10% fast
at 100 kph). I'm pretty certain the current ADR is based on an
international standard. There have also been a number of changes in
the way the relevant ADR's are worded since they first came into
effect.
The Navara speedo, being 10% fast at 100 kph, is right on the limit of
the compliance requirement. More than likely you'll find the odometer
is well within it (with some makes I've checked being extremely
accurate).
--
John H
Noddy
> Using an HTC Tytn II
>
> If your Nokia runs either Win Mobile or Simbian then most of the GPS
> software for mobiles will have a version
>
> head over to www.austech.info and www.ppcwarez.org
> and go through the GPS forums
> you might find that you can get Tom Tom or the Sygic McGuider software
> running on it also
>
> while you're there check out the other software apps available
Will do. Many thanks.
--
Regards,
Noddy.