How much does car fuel consumption differ with and without air conditioning?
2 Answers
The difference is 20%. The car air conditioning accounts for about 20% of the engine's power, so using the air conditioning consumes a portion of the engine's power, leading to an increase in fuel consumption. The specific increase in fuel consumption depends on the car's displacement and speed. Details are as follows: 1. Impact on fuel consumption: For a car that typically consumes 10 liters per 100 kilometers, using the air conditioning can increase fuel consumption by about 2 liters. The effect of air conditioning on fuel consumption is very noticeable, while the impact of different fan speeds is relatively smaller. For example, assuming a car is used for urban commuting with an average fuel consumption of 10 liters per 100 kilometers. 2. Reasons for the increase: Taking an average daily driving distance of 25 kilometers: driving 25 kilometers consumes 2.5L of fuel = 16.1 yuan (6.44 yuan/liter); with air conditioning, fuel consumption is 3L = 19.32 yuan: an additional cost of 3.22 yuan. The car's engine essentially powers the air conditioning compressor, so when the cooling air conditioning is turned on, the pressure on the car's engine increases, requiring more gasoline to burn for power. This is why sometimes when the cooling air conditioning is turned on while driving, the car's power feels slightly weaker, due to the increased pressure on the engine.
I've been driving for over a decade, and using AC does noticeably increase fuel consumption. One summer on the highway, my fuel consumption was 8L/100km without AC, but with AC it jumped to 9.5L, roughly a 20% increase. In stop-and-go traffic, it's even worse—the repeated cycling of the AC compressor can increase fuel consumption by up to 25%. Rolling down the windows? That works at low speeds, but once you hit 80 km/h, the increased wind resistance makes it even less efficient than using AC. Older cars are affected more—my decade-old SUV saw nearly a 30% increase in fuel consumption after the compressor aged. My advice? Don’t set the temperature too low; 24°C is the most economical.