Cars with ambitious speedometers
Discussion
Mr E said:
The Elise is 140 or 160, which seems optimistic.
Assuming it's the same as mine, the highest number is 140 although the bars actually go up to 150. The top speed is quoted as 131 (which feels about right to me) so 140 seems reasonable enough. 150 is certainly optimistic but there don't seem to be many cars where the speedometer doesn't go at least 15mph over the top speed. Edited by kambites on Friday 13th January 17:55
kambites said:
Assuming it's the same as mine, the highest number is 140 although the bars actually go up to 150. The top speed is quoted as 131 (which feels about right to me) so 140 seems reasonable enough. 150 is certainly optimistic but not as bad as the same speed on a transit. 
I tend to find the bodywork starts flexing in an alarming fashion at three figure speeds......it's more of a driver limit....
Always wondered why modern "normal" cars don't have more accurate dials at lower speeds, ie why there's not more emphasis on > 80mph then after that it becomes less accurate, as in... not explaining this well... but say the 75% of the range of the dial is taken up by 0 o 80mph and the rest is squeezed in for whatever figures the car probably won't ever see in it's lifetime. With speed signals coming from the ABS now, it'd be simple...
Edit: Having read that back, it makes bugger all sense... plus just noted those Vauxhall dials above do have it! The size of each 10mph increase on the gauge gets smaller, the faster the car is going.
Edit: Having read that back, it makes bugger all sense... plus just noted those Vauxhall dials above do have it! The size of each 10mph increase on the gauge gets smaller, the faster the car is going.
Edited by Davie on Saturday 14th January 13:15
Davie said:
Always wondered why modern "normal" cars don't have more accurate dials at lower speeds, ie why there's not more emphasis on > 80mph then after that it becomes less accurate, as in... not explaining this well... but say the 75% of the range of the dial is taken up by 0 o 80mph and the rest is squeezed in for whatever figures the car probably won't ever see in it's lifetime. With speed signals coming from the ABS now, it'd be simple...
Edit: Having read that back, it makes bugger all sense... plus just noted those Vauxhall dials above do have it! The size of each 10mph increase on the gauge gets smaller, the faster the car is going.
Yep, definitely some Vauxhalls and VWs do what you describe. Probably others tooEdit: Having read that back, it makes bugger all sense... plus just noted those Vauxhall dials above do have it! The size of each 10mph increase on the gauge gets smaller, the faster the car is going.
Edited by Davie on Saturday 14th January 13:15
KevinCamaroSS said:
sebhaque said:
I was having a look at a 1.8 Audi A4 earlier and noticed that the speedometer went to 180mph. I know the speedos are standardised across the different engine options of a car, but I did chuckle at a car with a 140mph top speed having a speedo pegged 40mph higher than the car could achieve from the factory.
Think RS4 as having the same standard speedometer.
Davie said:
The irony being, she has a Mk5 Astra and despite the many miles I've driven it... I never even noticed that.
I can however confirm it won't do 160mph.
I noticed after I'd had mine for about 6 months - one day I realised that 70mph was in the middle of the dial but it went to 160, not 140. Then I looked closer and realisedI can however confirm it won't do 160mph.
This is another great thing from Saab. Speedo is weighted to the lower figures (0-90 is 6 till 3). Then 3 till 6 is 90 to 160mph (The cars top speed). What is even more awesome is that if you are traveling below 87 MPH with night pannel on only 0-90 lights up. Go above this speed and the rest lights up 
.
As mentioned it also appears on Vauxhall although most likely ripped from Saabs.
.As mentioned it also appears on Vauxhall although most likely ripped from Saabs.
Edited by BricktopST205 on Saturday 14th January 14:10
h0b0 said:
RDMcG said:
My 991RS has a 350 km/h speedo.....217 MPH. Not even close. Maybe 190 in effect conditions.
They have allowed for the vast over reading of Porsche speedos. Mine reads over 10% over actual speed and that's even with the optional 21" wheels. A variance of 1% accuracy (for wheel speed, taken from a Hall sensor) in the serial production of speedometers with pointers driven by stepper motors should be feasible.
Porsche specifies the accuracy of their speedos in accordance to homologation requirements:
UN ECE R39 said:
5.3. The speed indicated shall not be less than the true speed of the vehicle. At the test speeds specified in paragraph 5.2.5. above, there shall be the following relationship between the speed displayed (V1) and the true speed (V2).
0 ? (V1 - V2) ? 0.1 V2 + 4 km/h
Basically that means when you're driving 100km/h, your speedo has to show a value between 104 and 114km/h. 0 ? (V1 - V2) ? 0.1 V2 + 4 km/h
At 190mph, this would read between 192.5 and 211.5 (theoretically - as the highest calibration speed is 75mph).
https://www.unece.org/fileadmin/DAM/trans/main/wp2...
Edited by Bodo on Saturday 14th January 14:54
sebhaque said:
I was having a look at a 1.8 Audi A4 earlier and noticed that the speedometer went to 180mph. I know the speedos are standardised across the different engine options of a car, but I did chuckle at a car with a 140mph top speed having a speedo pegged 40mph higher than the car could achieve from the factory.
It also looks like the speedo isn't weighted (where the lower speeds take up more of the gauge), so your legally useable speedo range is from the 6 o'clock to the 10 o'clock position.
Anybody else know of some similarly ambitious speedometers?
That really, really pissed me off on the nasty repmobile Audis I used to have to borrow from work. They confine the actual bit of the speedo you use to 1/3rd of the dial area, make it harder to see accurately what speed you are doing at a glance. If they will insist on giving a car that will struggle to do 130mph a speedo that goes up to 180mph they could at last weight it as you say.It also looks like the speedo isn't weighted (where the lower speeds take up more of the gauge), so your legally useable speedo range is from the 6 o'clock to the 10 o'clock position.
Anybody else know of some similarly ambitious speedometers?
Must be another part of the amazing VAG ergonomics that I just don't get, like armrests that foul the handbrake. It would be poor for a Chinese car and yet people just accept it.
Bodo said:
h0b0 said:
RDMcG said:
My 991RS has a 350 km/h speedo.....217 MPH. Not even close. Maybe 190 in effect conditions.
They have allowed for the vast over reading of Porsche speedos. Mine reads over 10% over actual speed and that's even with the optional 21" wheels. A variance of 1% accuracy (for wheel speed, taken from a Hall sensor) in the serial production of speedometers with pointers driven by stepper motors should be feasible.
Porsche specifies the accuracy of their speedos in accordance to homologation requirements:
UN ECE R39 said:
5.3. The speed indicated shall not be less than the true speed of the vehicle. At the test speeds specified in paragraph 5.2.5. above, there shall be the following relationship between the speed displayed (V1) and the true speed (V2).
0 ? (V1 - V2) ? 0.1 V2 + 4 km/h
Basically that means when you're driving 100km/h, your speedo has to show a value between 104 and 114km/h. 0 ? (V1 - V2) ? 0.1 V2 + 4 km/h
At 190mph, this would read between 192.5 and 211.5 (theoretically - as the highest calibration speed is 75mph).
https://www.unece.org/fileadmin/DAM/trans/main/wp2...
Edited by Bodo on Saturday 14th January 14:54
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