Imagine you're late for a wedding. The ceremony is 25 kilometres away and you've only just pulled out of your driveway. You peel around the corner, accelerate hard to get you up to 120 km/h and hope like heck you make it.

Actually, even a slight reduction in travel time doesn't compensate for the added fuel consumption and cost. For a typical 25 kilometre trip going 120 kilometres per hour vs. 100 kilometres per hour, you'll only save two and a half minutes of time but you'll use about 20 per cent more fuel.

Many drivers have reported that they use up to 15 per cent less fuel by acting on the feedback they get from an instantaneous fuel consumption gauge.

If your vehicle does not have a display, it may be possible to install one. Many vehicles manufactured after 1996 can easily be retrofitted with display systems that provide a range of information, from the cost of fuel per trip to an estimate of the vehicle's carbon dioxide (CO2) emissions. And you get the information in real time so you can react accordingly. Some newer vehicles not only report fuel consumption but also analyze speed variations, shift points for manual transmissions and driving behaviors such as acceleration and braking times.