Many drivers have reported 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 behaviours such as acceleration and braking times.
Natural Resources Canada has a number of gauges available for loan to driving educators. If you're interested, contact email@example.com.