Which Consumes More Fuel: Driving with Windows Down or Air Conditioning On in Summer?
2 Answers
On urban roads, using air conditioning clearly consumes more fuel than driving with windows down. However, on highways at 70 km/h, the fuel consumption between driving with windows down and using air conditioning is the closest. Below 70 km/h, driving with windows down saves slightly more fuel, while above 70 km/h, driving with windows down consumes more fuel. Reasons for High Fuel Consumption with Air Conditioning: Setting the air conditioning to 25 degrees Celsius is most suitable. One of the main reasons for high fuel consumption in summer is the excessive use of the car's air conditioning. Therefore, reducing the fuel consumption caused by the air conditioning will lower the vehicle's actual fuel consumption. Some car owners set the air conditioning to the lowest temperature to cool the interior faster. This causes the air conditioning pump to run continuously and the blower to operate at high speed, which actually increases fuel consumption. Additionally, a large temperature difference between the inside and outside of the car can make people more prone to catching a cold. Methods to Save Fuel with Air Conditioning: Experts suggest opening the windows before turning on the air conditioning. Prolonged use of air conditioning increases engine load and fuel consumption. After entering the car, owners should first open the windows to let out the hot air, then turn on the air conditioning. Periodically adjusting the air conditioning settings and avoiding constant high-speed operation can help save fuel.
I've been driving for over a decade and have indeed struggled with this issue during summers. For city driving, keeping the windows open barely affects fuel consumption since speeds are low. But when you hit the highway, once you exceed 80 km/h, the wind resistance from open windows becomes significant - it can cost you 1-2 liters more fuel than using air conditioning! My old Camry's real-world tests showed that running AC for 100 km only costs about 8 yuan extra, whereas driving with windows down on highways actually burns more fuel. However, on cooler night routes I occasionally turn off the AC and crack the windows slightly - the natural breeze feels quite comfortable, provided speed stays below 60 km/h.
