Speedo Adjustment For Bigger Tyres

[Glenn Board]

Before and after by mistake!

 

[Glenn Board]

Well since using the van, the speedo does work more actually, however the actual mileage recorded on the MFC is now around 10% less that what has actually been covered, this is also affecting other MFC readings, so any idea or how this can be sorted please?

 

[xpfloyd]

Why would the mileage be less by so much?

 

[Glenn Board]

I made a trip which is usually around 630KM, yet it was recorded as 565KM however the speedo now reads correctly and not over as standard, i will do a few more checks, but i am thinking that the larger tyres have put this out but corrected the speedo!

 

[xpfloyd]

Assuming your new wheel/tyre combination has a circumference close to the existing (as it should have), then there shouldn’t be an error in distance.

 

[Glenn Board]

Hi, after the conversion the speedo reads virtually bang on compared to GPS on my phone, however the trip computer, MFC and millage are now recording approximately 8% lower, for example on a 610km trip recorded a trip of 565km, any ideas where i can correct this using VCDS to match correct tyre size?

 

[mmi]

Hi, after the conversion the speedo reads virtually bang on compared to GPS on my phone, however the trip computer, MFC and millage are now recording approximately 8% lower, for example on a 610km trip recorded a trip of 565km, any ideas where i can correct this using VCDS to match correct tyre size?

AFAIK the adjustment of speedometer and odometer go hand in hand. The speedo adjustment is described in Speedo Adjustment With Vcds but any adjustment made is reflected also to odometer (+others in MFD) with same percentage.

 

[Glenn Board]

Ok, so it must be a default that the speedo is always over reading as most cars are.

 

[Desmoben]

The winter tyres option does not adjust the speedo, it just adds a warning if you exceed the speed you set.

The oversize tyres might correct your speedo to exact instead of reading over. You can't adjust it in vcds as far as I know.
There will be no issue with cruise..

Nice tyre, not too noisy, had a set on my Touareg for a while.
The seikel is great on the road. The California is loaded up all the time but you wouldn't know it.

Sorry for jumping in on this old thread. Remove if not allowed.

Hi Loz, you were good enough to answer a few of my newbie questions a couple of months back re BFG’s and Speedo error and poss ACC errors etc.
I’ve finally ordered VCDS from Gendan - but I honestly haven’t a clue how to use it to code out the Speedo error caused by my oversize rubber and wondering if you might possible be wiling to assist?
Worried as I’ve read it’s different to coding theT6 …and people reporting that when they make a change (and get it wrong) it doesn’t seem to be reversible …. Eeek!

I’ve not actually received my package yet - in tomorrow’s post (fingers crossed).

Thanks in advance,
B

 

[Glenn Board]

Hi have just changed my wheels and tyres from 205/65/R16 to 245/65/R17 and by speedo is out now by roughly 7kph when doing 120kph on the GPS.

Does anyone have any instructions I could use to update this with VCDS? Thanks.