My car does the same thing, although in MPH instead of KPH. I've verified that my speedometer consistently reads 5mph faster than what I'm really going. This is with my GPS, with the radar installations, and I've even used those little mile-marker signs in Oregon in coordination with my cruise control.

I wonder if this is a conspiracy by the car companies and/or the government to make us slow down? I've got a call in to CarTalk with this very question. Maybe they'll put me on the show with it?

I've allways thought that the various makers of cars made the speedometers show a little too much, to be on the safe side. If they showed to little, you could - at least in the US, blame the maker of your car that i wasn't your fault that you were speeding.

There was a case in Denmark, where a lady in the middle age was speeding to an exent that she were about to loose her license (+70% over given speedlimit in Denmark) - She blamed the cruisecontrol in her Ford Mondeo. The case was dropped, as it turned out that the cruisecontrol were infact faulty and kept increasing the speed. You should have thought that she notised, because she was caught driving 195km/t in the freeway. (Limit is 110kmt + 70% = 186kmt)

Another story, but goes well in this thread - i was once not so long ago (months) caught driving 230+ kmt on the freeway and was able to talk my self out of it. Didn't even get a fine!

Cheers

Kaare