How to Calculate Average Car Fuel Consumption?

[VonLucy]

Car fuel consumption is calculated by dividing the amount of fuel consumed by the distance traveled in kilometers. Related Information: 1. Constant Speed Fuel Consumption: Constant speed fuel consumption refers to the fuel economy indicator when a car is driving at a constant speed on a good road surface. Since constant speed driving is a basic operating condition for cars on highways, and this type of fuel consumption is easy to measure, it is widely adopted. For example, France and Germany use the constant speed fuel consumption at 90Km/h and 120Km/h as the main evaluation indicators for fuel economy. 2. Road Cycle Fuel Consumption: Road cycle fuel consumption is a fuel economy indicator measured when a car is driven in repeated cycles according to specified speeds and time protocols on the road, also known as multi-condition road cycle fuel consumption. The speed and time protocols specify various driving conditions included in each cycle, as well as the shifting times, braking and stopping times, driving speeds, acceleration, and braking deceleration values for each cycle.

[DelJulia]

I usually calculate fuel consumption in a simple and practical way. Every time I fill up the tank, I note down the current mileage. When I refuel next time, I check how many kilometers I’ve driven. For example, if the odometer showed 5,000 km at the last refueling and the fuel light came on at 5,300 km this time, then I divide the 300 km by the amount of fuel added during the second refueling. Last week, I added 30 liters of fuel after driving 450 km, so the fuel consumption is roughly 30 liters/450 km multiplied by 100, which comes out to 6.7 liters per 100 km. This month, I specifically tested the difference between city commuting and highway driving. Surprisingly, driving on the highway with the AC on was more fuel-efficient than stop-and-go city traffic. I recommend testing at least two or three full tanks for accuracy—keeping a small notebook has been really helpful. Now, whenever I see the average fuel consumption displayed on the dashboard, I verify it with my actual data, and the margin of error is usually within 0.5 liters.

[TessaLynn]

Last month, I took my family on a self-driving trip and carefully calculated the fuel consumption for the entire journey. Before setting off, I filled up the fuel tank until the automatic pump stopped, noting the odometer reading of 28,740 kilometers. Along the way, I topped up the fuel at three service areas, each time filling until the pump stopped. When I finally returned home, the odometer showed 29,380 kilometers, with a total of 48 liters of fuel added over the three refuels. Dividing the total distance of 640 kilometers by the amount of fuel used, the fuel consumption came out to 7.5 liters per 100 kilometers. I noticed that carrying too much luggage in the car increased fuel consumption by about 0.8 liters. While a mobile app can also assist in recording this, I prefer calculating it manually myself. Additionally, I can manually switch the trip meter when driving on different roads. Using cruise control for long periods does indeed save more fuel compared to manual acceleration, especially on undulating mountain roads.

[DiCarter]

Calculating fuel consumption requires special attention to method. It's essential to fill up to the same fuel level each time, with the automatic nozzle shutoff being the most accurate. Recently compared the car's displayed fuel consumption with manual calculations: the display consistently reads about 0.3 liters higher. Drove 200 km on the highway, deliberately maintaining a steady speed of 100 km/h, and used 2 liters less fuel than usual. An experienced driver taught me a simple calculation method: run a full tank for 500 km then refill to full – it really works. Recommended to wait for RPM to stabilize after cold start before setting off, this trick helped me save 5% on fuel.

[Jacob]

My driving instructor taught me a super practical trick. Every time the fuel light comes on, reset trip meter A, drive to the next gas station and fill up until the pump automatically stops, then record the liters of fuel added and the distance traveled. Last Friday when the fuel gauge light came on, the mileage was 12,450. When I reached 12,830, I added 32.5 liters of fuel. Burning this amount of fuel over 380 kilometers equates to 8.55 liters per 100 kilometers. I particularly noticed that slamming on the brakes or accelerator increases fuel consumption by about 10%. Now, if I'm stopped at a red light for more than 30 seconds, I turn off the engine. When driving in the city, I try to anticipate road conditions as much as possible to minimize braking, which is the most fuel-efficient approach.