Smartphone apps correct speedo error

A free app for your smartphone could save you money and your licence.

It's already saved me an hour of my life. And eliminated a day's worry about speed cameras.

Speedometer error has become a big issue since the Victorian crackdown on speeding with a tiny 3km/h tolerance, all the way to 110km/h. Australian design rules allow speedos to read 10 per cent over plus 4km/h (they can't read under), so chances are you're travelling slower than your speedo says.

The digital speedometer app allows you to measure your speed more accurately by using GPS.

On a recent trip, I discovered more than a 10 per cent error in the speedo of the Hyundai i30 I was driving. It was then easy to adjust my indicated speed to my real speed, without worrying about going over the limit.

It seems a little crazy at first to be sitting with the speedometer pegged at 120km/h on the freeway but I know that was less than 110 in the real world. And it's a similar story all the way down to 60km/h, once you have some GPS reality.

In more than 10 hours of driving in 100 and 110km/h highway zones I ended up saving over an hour on my trip time.

And not once did I fear a speed camera or a police car going the other way.

I've tried a couple of other apps and measured the accuracy of several speedos. All the apps do the job and every speedometer has been reading high — at least one piece of good news when we're all worried about fines and accruing demerit points.