speedo accuracy ... aded video

[STdemoniac]

hi guys, any of yours LC have same different if compare sat nav speed and clock ??
if i driving by clock 70mph, then sat-nav shows 65mph, if be clock 60mph, then be sat-nav 55... any idea ? tyres 225 45 R17
thanks

 

[Murdered LCR]

All speedos are out on any car

 

[STdemoniac]

All speedos are out on any car

but why ? on my previous car (passat) speedo wrong for abouth 3miles only, on my LC
5miles (!) ... and what interesting i do driver job, i`am driving lot of different HGV`s, and speedos are correct if compare be sat-nav just some lorrys have small different (maximum 2miles)

 

[LEE69]

If you got caught for speeding maybe the manufacturer could be held liable?

 

[SEATgod]

At 70 mph you can see up to a 5 mph difference! BUT, yours is the wrong way round.

If your Sat Nav showed 70 mph your speedo should show less, not more.

There are lots of options, wrong wheels and tyre size, wrong wheel bearings or damaged reluctor ring (depending on ABS setup) or wrong ABS coding etc.

When did it start happening, any work etc carried out lately?

 

[crimeblitz]

my tomtom shows im going 5 mph slower than my speedo at 70 and im running 17" 225 45 17. Just chalked it up as one of those things

 

[SEATgod]

So Tomtom says 65 an speedo says 70?

Wrong way round mate...something isn't right!

What about the other things I mentioned above?

 

[STdemoniac]

So Tomtom says 65 an speedo says 70?

Wrong way round mate...something isn't right!

What about the other things I mentioned above?

i jus speak with car mechanic, and he says, that normal, if ur speedo says 70mph, the real speed ( follow sat-nav, or speed gun) can be in about 5mile less (65mph)

everything around car looks ok, tyres 225 45 R17`, ABS fine, no fault , scaned with vag-com

 

[SEATgod]

Sorry mate misunderstood you, thought your speedo was over reading.

So your Tomtom always reads LOWER than your speedo? If so thats rights!

If your Tomtom is reading HIGHER than your speedo then that is wrong, but you can change the ABS coding which has a K correction for the speedo.

 

[STdemoniac]

So your Tomtom always reads LOWER than your speedo? If so thats rights!

yeap Tomtom reads lower speed than speedo

but you can change the ABS coding which has a K correction for the speedo

what ist that? and how to possible change?

 

[gdjohny]

good question. Mine is off by 10 Kmh

 

[Muttley]

Construction and use regulations. Speedos can overread by up to 10%, but must not underread at all. This means that they are deliberately manufactured to be about 5% high. This is to stop any possibility of the speedo being used as an excuse if you're caught speeding.

http://www.speed-trap.co.uk/Accused_Home/Rules_useage/The_Law.htm

 

[CupraTim]

My speedo said 160mph in my LCR but satnav read 154mph when I gave it some around the M25 at 3am. My LCR was still giving more - it was me that chickened out! The large long sweeping corners of the M25 suddenly become very sharp when driving fast :/

 

[JPS1]

i`am driving lot of different HGV`s, and speedos are correct if compare be sat-nav just some lorrys have small different (maximum 2miles)

HGV Tacho's are calibrated every 2 years a car is not so accurately calibrated

 

[Dabbalz]

Don't bother trying to change it, i'd rather be going under the speed limit and keep my licence clean.

Still, I'd have thought it would be summat you could do with VAGCOM as it's a sensor these days so electronically controlled.
If you cant I don't know, changing the sensor?? Or even going as far as changing the speed rotor (reluctor ring) in the gear box or the ABS reluctor ring if speed sensing is part of the ABS system????

 

[Dabbalz]

My speedo said 160mph in my LCR but satnav read 154mph when I gave it some around the M25 at 3am. My LCR was still giving more - it was me that chickened out! The large long sweeping corners of the M25 suddenly become very sharp when driving fast :/

Like a Porsche on the German autobahn i watched on TV. OUCH!

 

[Zlash_eX]

If the sat nav reads a lower speed than your speedo then that's fine. They're usually out by a few percent.
For example: once my speedo was at 80, sat nav said 75/76.

It's just sad that my car is not as fast as I think it is :'(

 

[STdemoniac]

i don`t care if difference be 2 or 3 miles, but now be 5 !!! any possibility adjust this with VAG-COM ?
what about mileage ? it also have error or be right ?

 

[Squidmato]

I found out yesterday that my clock on the LC is 5mph out compared to the sat nav through all of the legal speed range! I put it down to the standard variance of the speedo but did find it odd to be such a large amount at 30mph.

In comparison; the Punto I had was a barley noticeable 1-2mph out at 30mph, about 4-5mph out at 70mph and 6-7mph out at certain higher speeds! Yes I spent allot of time on long motorway journeys geeking out at this

 

[STdemoniac]

i find this adjustment for fuel gauge only, nothing for speed gauge ...

http://www.diyrepo.com/files/2011/3/3/vwvortex_forums_diy_-_adjusting_the_displayed_fuel_gauge_level_with_a_vag-com_id3208286.pdf

maybe possible adjust speed gauge in same way as fuel ??