Speedometer overclocking

[andrew1986]

Hi guys I've just bought myself a new car (Nissan note)

Anyway what I'm trying to find out is are the speedometers in your car supposed to be set to overclock by any minimum amount?

I'm asking as in my old car (Clio) it overclocked by about 10% however the speed seems completely accurate judging by my sat nav and one of those current speed signs when my speedo is bang on 30 my sat nav and the sign both read the same

I took it on the motorway for the first time tonight and when my speedo read 70 the sat nav read 69 so there appears to be little to no overclocking at all

Edited by andrew1986 on Saturday 4th June 00:59

[Red Devil]

How old (MY) was your Clio and how recent is the Nissan? The more modern the car the more accurate the speedo reading is likely to be.

[andrew1986]

The clio was a 51 plate the note is a 10 plate cheers for the reply

[DoubleD]

All cars are different. But now you know what your real speed is so happy days.

[PH XKR]

they tend to overread for several factors but namely due to the fact idiots don't inflate tyres properly. It is highly unlikely your speedo is 100% accurate as GPS tends to be off in anything but top end systems and those "your speed is" type devices are calibrated to condition you that your speedo is correct (ie you are doing 27 but it says 30 etc)

[agtlaw]

The type approval process for cars requires the speedometer to show not less than true speed and a maximum tolerance of true speed + 10% + 4 km/h at 40, 80 and 120 km/h.

[sunnydude]

I know you can turn off 'adjusted' speed on BMWs by coding (i.e. Show real speed), but I don't know about Clio's

[Stoofa]

In the UK a speedometer must never show an indicated speed less than the actual speed.
The indicated speed must not exceed 110% of the actual speed plus 6.25mph.

So, for example.
Vehicle travelling at 50mph - the speedometer must show a reading between 50mph & 61.25mph