The Government's Energywise website has launched an online tool designed to illustrate how small changes to driving style and car maintenance can lead to big fuel savings.
Energywise spokesman Simon O'Brien said the holiday period was busy with traffic and so was the perfect time to focus on saving fuel.
A standard family station wagon travelling 400km, about the distance from Dunedin to Alexandra and back, used about 25% less fuel if a fuel-efficient driving style was adopted and the car was well maintained.
How you drove affected the fuel economy of a car, he said, ''because bursts of acceleration require gulps of fuel, making your car thirstier.
''If the roads are busy, chances are overtaking a couple of cars just to get stuck behind the next queue will not save you much time.''
It was best to relax ''and enjoy the scenery'', he suggested.