Police do not use the factory speedo. They have a very accurate electronic one that is mounted to the dashboard. These are calibrated on a prescribed service regime.

Hello Laurie,

So exactly when will the RTA make available these "very accurate electronic one" (speedos) cheaply so that we can all fit them to the dashboard our 30+ year old cars, so that then we will all be on a level playing field with the police?

You may have to calibrate the speedos fitted to your 30 year old cars. I did cost me $150 Attspeed Instruments Liverpool. Saves on traffic tickets
Police speedometers have to be accurate for the equation to be spot on when utilising Radar for speed readings of approaching or departing vehicles.

Isnt it true that a police officer that has been specifically trained (e.g. Highway Patrol officer) can book you without using a radar or calibrated speedo.

I'm not sure how even "calibrated" 30 year old speedos can be accurate within 1 kmh as demanded by the RTA.

Even if the 30 year old speedo were to be precision calibrated, would not errors still occur when taking into account parallax error (ie the errors incurred by the drivers eye position (which constantly changes) with respect to the speedo needle, and the dial, which at best is calibrated to only 5kmh?? (as with my Mk2 Escort).

As an engineer, to me, the idea of precision calibrating sounds like a bit of firfy, and well beyond the expectations and limitations of 35+ year old technology.

Even manufacturer's of modern GPS technology which is touted to be the most accurate form of speed indication in a motor vehicle today, advise they can only indicate to an accuracy of +/-3kph. The government needs to get off the grass...

Until to road surface is fitted with precision sensor lugs/teeth and vehicles with precision tooth sensors...it is impossible to achieve 100% speedometer accuracy...that fact doesnt change no matter how much anyone wants it too!!

what about some of us that may have cars fitted with MPH speedo's, it can be quite difficult to do 62.14 MPH to do 100KPH exactly [(#)]

quote:

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Originally posted by laurie

You may have to calibrate the speedos fitted to your 30 year old cars. I did cost me $150 Attspeed Instruments Liverpool. Saves on traffic tickets
Police speedometers have to be accurate for the equation to be spot on when utilising Radar for speed readings of approaching or departing vehicles.

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in my EF Falcon i have an EX-Police speedo, which i can calibrate to +/- 10%.

but since putting new tires on, its probably wrong. better do a few burnouts to get the treads down now.

Revenue raising!