- Gas up full tank at your favorite fuel station, preferably same station, same pump, same octane rating, and if you can, around the same time of the day. Varying day temperatures cause fuel to expand or contract, which affects the volume of fuel pumped inside your vehicle.
- Before leaving the station, make sure you record your present mileage or remember it. For example, say 1,500km. Some cars again have the cumulative mileage count (does not reset) and the trip counter which you may reset from time to time. Use whatever is easier for you, the objective later on is to measure how many kilometers you have run.
- Go on your normal trips, may it be city driving, highway driving, etc. Preferably, you use the usual route for your daily travels, such as your way to and from work. Factors such as traffic volume and driving speed and travel time will definitely affect the measurement so as much as possible, the driving situations should be similar throughout the measurement. No sudden out of town trips flying at high speeds on the expressway because this will definitely be an outlier, and efficiency in this scenario should be measured separately.
- When the time comes that you need to gas up again, have a full tank once more and note two figures: number of liters needed to achieve full tank, and your mileage reading at this second full tank. Again, preferably same pump, same station, around the same time of the day. For example, say 20L and 1,750km.
- With these 3 figures, we can now compute the period’s fuel efficiency:
Compare as well this fuel efficiency with other people driving the same vehicle as you do.
And lastly, be mindful on how you can still improve your efficiency by adjusting your driving style. Shift in lower rpms? Less idling? More cruising? Less heavy foot on the gas pedal?