2003 A4 3.0 Speed limiting in ECU
#41
Guest
Posts: n/a
Re: 2003 A4 3.0 Speed limiting in ECU
Andy Turner wrote:
> On Tue, 12 Apr 2005 22:59:12 +0100, Graham <me@privacy.net> wrote:
>
>
>>Andy Turner wrote:
>>
>>>On Mon, 11 Apr 2005 17:52:39 GMT, somebody@anywhere.org wrote:
>>>
>>>
>>>
>>>>Please don't chastise me. But in the name of science I took my A4 out
>>>>on an empty highway near me yesterday. After some test runs up and
>>>>down this road to nowhere, looking for speed traps. I tested to see
>>>>if it was indeed programmed not to exceed 130MPH. At 135MPH I felt my
>>>>question had been answered.
>>>
>>>
>>>At an indicated 135mph, I'd expect you to be doing less than 130mph.
>>
>>Indeed, prob. < 120mph. If you can, borrow a GPS unit which will give
>>you a more accurate "actual" speed. My GPS unit tells me that when I'm
>>doing 70mph, it's actually 65. The differential gets greater the faster
>>you go (compared to say 30 mph).
>
>
> Funnily enough, I tried the very same thing tonight. It's tricky to
> say for sure because I had to keep glancing at two things (as well as
> the road of course.. if I had cruise it might have helped), but I
> eventually decided that 70mph on the dash was 66mph on the GPS.
>
>
> andyt
>
I always use a Garmin GPS and have found the Audi speedometer to read so close
to the GPS at all speeds up to 85 mph that I can not tell if there is any
difference at all. This was in three T44s and one 98.5 A4.
The GPS is supposedly accurate to 0.1 mph and updated each second.
Tony
#42
Guest
Posts: n/a
Re: 2003 A4 3.0 Speed limiting in ECU
Andy Turner wrote:
> On Tue, 12 Apr 2005 22:59:12 +0100, Graham <me@privacy.net> wrote:
>
>
>>Andy Turner wrote:
>>
>>>On Mon, 11 Apr 2005 17:52:39 GMT, somebody@anywhere.org wrote:
>>>
>>>
>>>
>>>>Please don't chastise me. But in the name of science I took my A4 out
>>>>on an empty highway near me yesterday. After some test runs up and
>>>>down this road to nowhere, looking for speed traps. I tested to see
>>>>if it was indeed programmed not to exceed 130MPH. At 135MPH I felt my
>>>>question had been answered.
>>>
>>>
>>>At an indicated 135mph, I'd expect you to be doing less than 130mph.
>>
>>Indeed, prob. < 120mph. If you can, borrow a GPS unit which will give
>>you a more accurate "actual" speed. My GPS unit tells me that when I'm
>>doing 70mph, it's actually 65. The differential gets greater the faster
>>you go (compared to say 30 mph).
>
>
> Funnily enough, I tried the very same thing tonight. It's tricky to
> say for sure because I had to keep glancing at two things (as well as
> the road of course.. if I had cruise it might have helped), but I
> eventually decided that 70mph on the dash was 66mph on the GPS.
>
>
> andyt
>
I always use a Garmin GPS and have found the Audi speedometer to read so close
to the GPS at all speeds up to 85 mph that I can not tell if there is any
difference at all. This was in three T44s and one 98.5 A4.
The GPS is supposedly accurate to 0.1 mph and updated each second.
Tony
#43
Guest
Posts: n/a
Re: 2003 A4 3.0 Speed limiting in ECU
Andy Turner wrote:
> On Tue, 12 Apr 2005 22:59:12 +0100, Graham <me@privacy.net> wrote:
>
>
>>Andy Turner wrote:
>>
>>>On Mon, 11 Apr 2005 17:52:39 GMT, somebody@anywhere.org wrote:
>>>
>>>
>>>
>>>>Please don't chastise me. But in the name of science I took my A4 out
>>>>on an empty highway near me yesterday. After some test runs up and
>>>>down this road to nowhere, looking for speed traps. I tested to see
>>>>if it was indeed programmed not to exceed 130MPH. At 135MPH I felt my
>>>>question had been answered.
>>>
>>>
>>>At an indicated 135mph, I'd expect you to be doing less than 130mph.
>>
>>Indeed, prob. < 120mph. If you can, borrow a GPS unit which will give
>>you a more accurate "actual" speed. My GPS unit tells me that when I'm
>>doing 70mph, it's actually 65. The differential gets greater the faster
>>you go (compared to say 30 mph).
>
>
> Funnily enough, I tried the very same thing tonight. It's tricky to
> say for sure because I had to keep glancing at two things (as well as
> the road of course.. if I had cruise it might have helped), but I
> eventually decided that 70mph on the dash was 66mph on the GPS.
>
>
> andyt
>
I always use a Garmin GPS and have found the Audi speedometer to read so close
to the GPS at all speeds up to 85 mph that I can not tell if there is any
difference at all. This was in three T44s and one 98.5 A4.
The GPS is supposedly accurate to 0.1 mph and updated each second.
Tony
#44
Guest
Posts: n/a
Re: 2003 A4 3.0 Speed limiting in ECU
somebody@anywhere.org wrote:
>
> It was tough enough looking at the speedometer. I assumed that the
> ECU would be using the same number as the speedometer, does this mean
> I have to run the test again?
Audis and VWs are designed to show a higher than actual speed on the
speedo. The ECU knows the real speed (to within the accuracy permitted
by variations in tire size due to wear, etc.) and there's a trick you
can do with the Climatronic to get it to show the true speed. (On the
Passat, it's fan-down, temp-down, and Econ all at the same time, then
use temp-up to reach option 16 - don't know if it's the same on an A4.)
I recently did this on my Passat and found that the difference was
about 3-4 MPH at 50.
--
Mike Smith
>
> It was tough enough looking at the speedometer. I assumed that the
> ECU would be using the same number as the speedometer, does this mean
> I have to run the test again?
Audis and VWs are designed to show a higher than actual speed on the
speedo. The ECU knows the real speed (to within the accuracy permitted
by variations in tire size due to wear, etc.) and there's a trick you
can do with the Climatronic to get it to show the true speed. (On the
Passat, it's fan-down, temp-down, and Econ all at the same time, then
use temp-up to reach option 16 - don't know if it's the same on an A4.)
I recently did this on my Passat and found that the difference was
about 3-4 MPH at 50.
--
Mike Smith
#45
Guest
Posts: n/a
Re: 2003 A4 3.0 Speed limiting in ECU
somebody@anywhere.org wrote:
>
> It was tough enough looking at the speedometer. I assumed that the
> ECU would be using the same number as the speedometer, does this mean
> I have to run the test again?
Audis and VWs are designed to show a higher than actual speed on the
speedo. The ECU knows the real speed (to within the accuracy permitted
by variations in tire size due to wear, etc.) and there's a trick you
can do with the Climatronic to get it to show the true speed. (On the
Passat, it's fan-down, temp-down, and Econ all at the same time, then
use temp-up to reach option 16 - don't know if it's the same on an A4.)
I recently did this on my Passat and found that the difference was
about 3-4 MPH at 50.
--
Mike Smith
>
> It was tough enough looking at the speedometer. I assumed that the
> ECU would be using the same number as the speedometer, does this mean
> I have to run the test again?
Audis and VWs are designed to show a higher than actual speed on the
speedo. The ECU knows the real speed (to within the accuracy permitted
by variations in tire size due to wear, etc.) and there's a trick you
can do with the Climatronic to get it to show the true speed. (On the
Passat, it's fan-down, temp-down, and Econ all at the same time, then
use temp-up to reach option 16 - don't know if it's the same on an A4.)
I recently did this on my Passat and found that the difference was
about 3-4 MPH at 50.
--
Mike Smith
#46
Guest
Posts: n/a
Re: 2003 A4 3.0 Speed limiting in ECU
somebody@anywhere.org wrote:
>
> It was tough enough looking at the speedometer. I assumed that the
> ECU would be using the same number as the speedometer, does this mean
> I have to run the test again?
Audis and VWs are designed to show a higher than actual speed on the
speedo. The ECU knows the real speed (to within the accuracy permitted
by variations in tire size due to wear, etc.) and there's a trick you
can do with the Climatronic to get it to show the true speed. (On the
Passat, it's fan-down, temp-down, and Econ all at the same time, then
use temp-up to reach option 16 - don't know if it's the same on an A4.)
I recently did this on my Passat and found that the difference was
about 3-4 MPH at 50.
--
Mike Smith
>
> It was tough enough looking at the speedometer. I assumed that the
> ECU would be using the same number as the speedometer, does this mean
> I have to run the test again?
Audis and VWs are designed to show a higher than actual speed on the
speedo. The ECU knows the real speed (to within the accuracy permitted
by variations in tire size due to wear, etc.) and there's a trick you
can do with the Climatronic to get it to show the true speed. (On the
Passat, it's fan-down, temp-down, and Econ all at the same time, then
use temp-up to reach option 16 - don't know if it's the same on an A4.)
I recently did this on my Passat and found that the difference was
about 3-4 MPH at 50.
--
Mike Smith
#50
Guest
Posts: n/a
Re: 2003 A4 3.0 Speed limiting in ECU
Mike Smith wrote:
>Wolfgang Pawlinetz wrote:
>>
>> Why would it? Which additional sensor would there be? And even more,
>> what sense would that make?
>
>It makes legal cover-your-*** sense, at least in the US.
Well, I'm not doubting that it makes sense to have a speedo which is
showing a little more than the actual speed. It's the law here as
well.
But I'm wondering where the ECU/Air Conditioning display should get
different info from.
IMO it's just the same information shown on another display.
Regards
Wolfgang
>Wolfgang Pawlinetz wrote:
>>
>> Why would it? Which additional sensor would there be? And even more,
>> what sense would that make?
>
>It makes legal cover-your-*** sense, at least in the US.
Well, I'm not doubting that it makes sense to have a speedo which is
showing a little more than the actual speed. It's the law here as
well.
But I'm wondering where the ECU/Air Conditioning display should get
different info from.
IMO it's just the same information shown on another display.
Regards
Wolfgang