Incorrect Speedometer - Golf mkVII?

[Guest001]

What I have noticed is that most people are aware of the speedo inaccuracy and seem to sit around an indicated 105/110 in 100 zones yet soon as they come to a fixed speed camera they all drop back to an indicated 100 or less. So much for having confidence in their speedo readings.

I think they just speed and to hell with it. Then slow down to under when passing speed cameras.

[DV52]

If anyone isn't happy with their speedo readout you can change it. I noticed the other day a setting in the menu for winter tyres that allows you to adjust the readout (Mk 6 R). Haven't fiddled with it. I just set cruise 5 above posted limit, 10 in 110 zones, and haven't had a ticket yet. From memory GPS and overhead gantry speed checks give 113 with cruise set at 120. Might be 1 or 2 higher.

Ryan_R: Hi. Alas, it may not be so easy to change the speedo reading on a mk7. I'm more than happy to be proven wrong on this assertion- please tell me how.

There are no adaptation channels in the mk7 about "winter tires " (I can only find a mention of "winter wiper position"). I've also tried looking for "distance impulse number" without success. One of the VCDS Gurus on the RT forum said that the only way to do it on MQB platform vehicles was to download the cluster software and modify the calibration - way too hard for me!

[DV52]

If you are so worried get a VCDS cable and adjust the settings.

Hillbilly: I have, and I can't! (see my reply to Ryan_R)

[wai]

Of course, this does mean that car owners get short changed if they have a warranty that limits km, and they end up running out of km rather than time.

[Guest001]

Of course, this does mean that car owners get short changed if they have a warranty that limits km, and they end up running out of km rather than time.

Untrue as the odometer is different to the speedo and still reads the correct distance, provided the tyres are the standard size.

[Guest001]

Hillbilly: I have, and I can't! (see my reply to Ryan_R)

Maybe different versions do and some dont.
We tried on the Polo but it has the cheap MFD and while it seemed the digits were alterable the end result was that speedo remained the same

[Mountainman]

Untrue as the odometer is different to the speedo and still reads the correct distance, provided the tyres are the standard size.

Mine doesn't. According to the odometer it indicates 100km and my Garmin says 99.1km. At an indicated 100km/h the Garmin says 95km/h.

[Kesh]

The car's computer will receive the true speed value from the speed sensor in the car so the trip meter won't be affected. In order to account for instrument inaccuracies, visual errors, tyre wear and to provide a buffer for us in case we accidentally jab the throttle and speed, the MFD and speedo seem to read 3kp/h higher.

I have my phone connected via bluetooth to my ECU, and when the MFD reads 70, the car reports 67, and when the MFD reads 80, my car reports 77.

[AdamD]

Ryan_R: Hi. Alas, it may not be so easy to change the speedo reading on a mk7. I'm more than happy to be proven wrong on this assertion- please tell me how.

That's Paul, not Ryan.

The Winter Tyres option in the MFD on the Mk6 is there to tell the car you're running tyres with a lower speed limit, and not a different speedo calibration. It doesn't allow you to specify a new tyre size or circumference etc etc.

If you do use VCDS to tweak the speedo settings (some have tried; most/all don't get the results they're looking for and end up reverting), then you will be throwing off the odometer in the car. Your speedometer should actually be very accurate if your tyres are of OEM-spec size (and it is this that drives the odo), but the instrumentation has a degree of error that is introduced to deal with legislative requirements (which themselves are there to do with margin for error courtesy of old/incorrect-sized tyres, poor driving habits, etc). The government is perfectly happy for you to do 92km/h in a 100 zone.

There is a solution to this problem. Buy an Autopolar FIS+ (once the Mk7 firmware is released) or similar, that interfaces directly into the canbus and displays the real vehicle speed, without any error introduced. That's what I do, and the reported speed matches up precisely with my GPS devices I've used to verify it.

[Guest001]

You can also see it in the secret menu in an RNS510 in other models. Dont know if you can do that in the Mk 7

[AdamD]

You can also see it in the secret menu in an RNS510 in other models. Dont know if you can do that in the Mk 7

I don't believe you can. But either way, looking at your headunit to check speed isn't exactly safe.

[Guest001]

I don't believe you can. But either way, looking at your headunit to check speed isn't exactly safe.

I dont actually and only use it to occasionally calibrate the HUD so my eyes never leave the road. LOL

[DV52]

That's Paul, not Ryan.


There is a solution to this problem. Buy an Autopolar FIS+ (once the Mk7 firmware is released) or similar, that interfaces directly into the canbus and displays the real vehicle speed, without any error introduced. That's what I do, and the reported speed matches up precisely with my GPS devices I've used to verify it.

Paul: my apology for the error!
Adam: Yes, I'm looking forward to the mk7 release of the FIS+. Any idea when?

You can also see it in the secret menu in an RNS510 in other models. Dont know if you can do that in the Mk 7

What secret menu? How do you access this menu on the RNS510 and I will try on the Discover media unit?

[Guest001]

Paul: my apology for the error!
Adam: Yes, I'm looking forward to the mk7 release of the FIS+. Any idea when?



What secret menu? How do you access this menu on the RNS510 and I will try on the Discover media unit?

Kamold will have a better idea than I about it on a Mk7 but in the 510 you need the later firmware which we get off here and then hold down the setup button for about 20secs.

[Golf Girl]

Yep its pretty common for new or vaguely new cars to be under in their speedo. My Mk6 golf is under by 8kph (110kph is really 102kph). Was the same for my 2006 Hyundi Getz out by 5kph. Look at it as a safety feature. I suspect it's deliberately done by the manufactures now because we are to stupid to follow the road rules.

Just know your difference then you can adjust your cruise control to match. Set yours to say 115kph and you'll still be under the speed limit but closer.