Federal legislation allows vehicle manufacturers in Australia to have a 10% variance in the speedometer.

Many people will, and do in other States & Territories, get speeding penalties when they believe they are obeying the law.

If you have already been fined for speeds of 142km/h in a 130 km/h zone, then this is already below the 10% error permitted in your motor vehicle speedometer calibration!

Also did you know that your speedodmeter will vary as your tyres wear?  Effectively your rolling diameter will change as your tyres wear or if you alter the size of your tyres.

Many people under the guidance of their tyre service centre increase the width of their tyres or profile for increased safety.  This can have a dramatic effect on the accuracy of your speedometer.

Just ask anyone who has moved from Victoria to the Territory as they now get booked for only 2km/ph over the speed limit.  Yes, that is correct at 102 km/ph in Victoria you will get a speeding fine!  This is not yet the case in the Territory but give it time and going buy the other Southern Restrictive States the Territory will no doubt follow.