Why Do Sedans Consume More Fuel in Winter?
3 Answers
There are several main reasons why sedans consume more fuel in winter: 1. Increased fuel consumption due to heating: In winter, the heating system uses the engine's coolant temperature to generate heat. Essentially, the blower fan directs the heat naturally produced by the engine into the cabin. When the weather is extremely cold, turning on the heater forces the engine to increase fuel injection and adjust the "ignition timing" to maintain optimal operating temperature, leading to higher fuel consumption. 2. Reduced battery efficiency: Winter days are shorter, requiring headlights to be on for longer periods compared to summer. Additionally, low temperatures slow down the chemical reactions in the battery's electrolyte, often resulting in battery drain. Moreover, cold starts in winter demand more power to overcome resistance, which is another factor contributing to increased fuel consumption.
I've been driving for over a decade, and winter fuel consumption is indeed higher than in summer, mainly because the engine takes longer to warm up. When the engine is cold, the ECU makes it inject more fuel, and slow water temperature rise means more fuel consumption. Another point is idling for too long - many people think they need to wait until the temperature gauge rises, but actually driving slowly 30 seconds to 1 minute after starting saves more fuel. Idling burns the most money! Also, tire pressure drops when it gets cold, and flatter tires increase friction, which can add up to 5% more fuel consumption. The heater is actually fine as it mostly uses waste heat from the engine, but turning on the AC for defrosting activates the compressor, which really consumes fuel.
Last time I heard from a mechanic that higher fuel consumption in winter is mainly due to thickened engine oil. When temperatures drop below minus ten degrees Celsius, the oil becomes as thick as paste, causing resistance to piston movement during startup, which requires burning more gasoline to drive the engine. Additionally, car batteries discharge faster in low temperatures, forcing the alternator to work harder to recharge during startup, inadvertently increasing the engine's load. Gasoline atomization efficiency also suffers, leading to poorer combustion efficiency compared to summer. I've noticed that for every 1°C drop below 10°C, fuel consumption increases by approximately 0.5%, especially noticeable during short commutes. It's recommended to switch to low-temperature engine oil instead of using the factory-specified summer-grade oil.
