GPS Speed display in RNS510?

[Swallowtail]

I tested mine this morning -

At an indicated 101 / 102 on the speedometer the MFD digital readout said I was doing 100 (and the cruise control was set to 100). The display in the AC controls (press up vent and AC buttons and the same time, then roll the left hand temp dial so it reads 19, then the right hand display show speed) was reading 92 / 93.

To me that is too much - at an indicated 102 I'd be fine with actually doing 98 or so, not 92. Just as likely to have people trying to climb up my rear on the freeway cos I'm going too slow.

You can change the margin of overreading in VAGCOM I believe. I need to do some digging...

[dazag]

I remember reading a post in www.briskoda.net that suggested how you could adjust the speedo calibration via the MFD - Does anyone have a link to that?? I've like to re-adjust mine to be more in line with the GPS, and also correctly set up the Fuel Economy settings to match.

[K1W1]

Fuel economy is based on distance travelled and fuel consumed not speed. Generally the odometers on cars are accurate (way more accurate than the speedos) so your fuel economy readings should not be affected by a speedo that is optimistic.

[Transporter]

I remember reading a post in www.briskoda.net that suggested how you could adjust the speedo calibration via the MFD - Does anyone have a link to that?? I've like to re-adjust mine to be more in line with the GPS, and also correctly set up the Fuel Economy settings to match.

I don't know how to do it in MFD but you can also adjust both independently in VCDS (vag-com).

[Swallowtail]

I tested mine this morning -

At an indicated 101 / 102 on the speedometer the MFD digital readout said I was doing 100 (and the cruise control was set to 100). The display in the AC controls (press up vent and AC buttons and the same time, then roll the left hand temp dial so it reads 19, then the right hand display show speed) was reading 92 / 93.

To me that is too much - at an indicated 102 I'd be fine with actually doing 98 or so, not 92. Just as likely to have people trying to climb up my rear on the freeway cos I'm going too slow.

You can change the margin of overreading in VAGCOM I believe. I need to do some digging...

OK, found the bit in VCDS to change it. The scale is from 0 to 7. Mine was already set to 6! So I set it to 7 and we went for a drive this morning. It's a little better - now an actual 100 is an indicated 105 / 106.

So that's an improvement at least.

Did a couple of other bits in VCDS while I had it connected - set emergency braking to activate flashers (common in Europe), and fixed up my rain sensing auto-close sunroof / windows.

Fuel economy you can set within a range of 85 to 115%. Comes from factory at 100%. SO if you work out that it is wrong you can adjust it using VCDS.

[gregozedobe]

Fuel economy is based on distance travelled and fuel consumed not speed. Generally the odometers on cars are accurate (way more accurate than the speedos) so your fuel economy readings should not be affected by a speedo that is optimistic.

True, but the fuel consumption reading on the MFD is (usually) also optimistic, and can be adjusted too (separately). But to be fair, Skoda readings seem to be a lot more accurate than VWs.

[dazag]

Fuel economy is based on distance travelled and fuel consumed not speed. Generally the odometers on cars are accurate (way more accurate than the speedos) so your fuel economy readings should not be affected by a speedo that is optimistic.

Strange, I thought you're odometer is tied to your speedo. So if I sit on 110km/h on the freeway for an hour, my odometer should read that I've traveled 110km over that hour. So what you're saying is I can sit on 110km/h but my odometer will be reading the speed different to be more accurate?? I don't think so, unless they receieve different speed signals?
Or you saying the fuel Economy readout should be accurate knowing that the Speedo is out a little it compensates??

What's the deal with the VAGCOM, please explain??

[Swallowtail]

The car gets the speed and has that internally. That can be seen through the Air con display. The odometer is driven from that. Then a variable is introduced for the speedo, so that it will never under-read. That is called the distance impulse. It is modifiable within a certain range using VAGCOM - www.ross-tech.com.

[Gav23]

Are all German cars speedo's this far out, or just VW's? I can't imagine I'd be impressed if I spent $150K on a Merc and it's speedo was out 10%! If Falcadore's and Hyundai's can have speedo's accurate within 2km (well the ones I've driven anyway), why can't VW?

Taking 10% off isn't difficult, but it is an unnecassary distraction to your driving, especially in busy city traffic.

[Graybags]

The speedo being out isnt a fault, just tweeked to indicate slower speed to stop people being fined, just that they are overly cautious in their tweeking.