Speedo is way out

[S3am]

Hi, got yet another problem with my s3

the speedo is way out , at 40 on the clock I drove through a radar and it came up as 46!6 mph under at 40 is a pretty huge gap.

Can an the speedo be calibrated ? I'm guessing this is a job that can't be done on the drive way, any ideas on cost of fix ?

 

[Trig0r]

You running a non standard wheel/tyre combo?

 

[S3am]

When I brought the car it ha 18" RS4 wheels with 235/40/18's
But I've read they can be spec'd as a factory option ??

 

[[Dave B]]

225/40/18's were standard optional fit...

 

[S3am]

I brought mine with 225's on the front and 235's at the rear

 

[desertstorm]

Difference between 225/40/18 and 235/40/18 is only 1.25% so thats not the problem.
You could check the cluster with VAG-COM to see if the impulse number is set correctly.
Different clusters have different options.

Speedometer fast error adjustment and correction - mk5, mk6 | VW TDI forum, Audi, Porsche, and Chevy Cruze diesel forum

Have you checked your speedo against GPS. You can get GPS speed apps for Android phones.

https://play.google.com/store/apps/details?id=com.codesector.speedview.free

 

[S3am]

Thanks for the reply and info. I have since checked against GPS and it's reading around 10% slower than the true speed.
I'll see if I can find somewhere with VAGCOM to see if I can resolve the problem .