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Block Heaters Save Fuel and Help the Environment

Starting a vehicle on a cold winter day can be a chilling experience. It can also be hard on your vehicle, pocketbook and the environment.

You'll use more fuel and create more emissions in the first minutes after a "cold start" than when the engine reaches normal operating temperature. When an engine starts up, it pumps oil throughout the engine block to lubricate moving parts. In a cold engine, the oil is thick and resists flow, so the engine has to work harder to overcome internal friction.

Fuel combustion is also less efficient in a cold engine, and the air-fuel mixture is richer – in other words, there is more fuel and less air in the mixture. (The mixture of fuel vapour and air must be in proper proportion for efficient combustion.) The combined effect is a sharp increase in emissions. On top of everything else, the catalytic converter doesn't work efficiently when it is cold.

You can help reduce the impact of cold starts – and reduce idling time – by using a block heater on cold winter days. This device warms the coolant, which in turn warms the engine block and lubricants. The engine will start more easily and reach its proper operating temperature faster. What's more, it won't have to work as hard to pump oil through the block.

At -20°C, block heaters can improve overall fuel economy by as much as 10 percent. For a single short trip at -25°C your fuel savings could be in the order of 25 percent.

Reduced fuel consumption will do more than save you money. It will also minimize greenhouse gas (GHG) emissions that contribute to climate change. Carbon dioxide (CO2), the most common GHG, is an unavoidable by-product of burning gasoline. Every time you turn on your vehicle's engine, you generate CO2 – and the more fuel you use, the greater your GHG emissions.

A block heater runs on electricity. To save money, invest in an automatic timer that switches the block heater on two hours before you plan to drive the vehicle (instead of leaving it plugged in all night). Usually this is all the time needed to warm the coolant and the engine.