Anti-idling myth busters

Anti-idling myth buster

Idling gets you nowhere. Here we clear up some common misconceptions about engine idling…

My engine needs to stay on to keep the battery warm.
False. Improved battery design has largely eliminated this threat. 

Turning the engine on and off wears it out.
False. It creates less wear and tear than idling. Electronic ignitions in modern cars have eliminated this problem.

Catalytic converters need to be hot to work properly.
True, but an idling engine does not keep a catalytic converter warm. They retain their heat for about 25 minutes after an engine is switched off anyway.

When it's cold I need to keep my engine running to keep my car and passengers warm 

It can take up to an hour for the engine to cool down. Turn your engine off but keep the ignition on and the fan blowing and the car will stay warm for some time.

Idling keeps an engine in better condition.
False. Idling means incomplete combustion, leading to a build-up of residue in an engine, increasing wear and tear.

Starting an engine uses more petrol than idling.
False. In fact, for a majority, engines idling for more than 10 seconds use more petrol that starting the motor.

The best way to warm up your vehicle is to leave the engine running for a few minutes.
False. You only need to run the engine long enough to get the oil circulating (about 30 seconds) before driving away.

Idling reduces wear and tear on your engine particularly when cold.
False. Idling creates wear and tear on your engine because fuel does not combust completely, and some fuel residue can condense on cylinder walls. Excessive idling can cause condensation to form in the exhaust, which may result in corrosion and reduced lifespan of the exhaust system. But the most severe damage is to the connecting rod bearings. This happens because of the relatively slow speed of the engine, more pressure is exerted on the bottom centre and top centre of the bearings.

Remember, as well as wasting fuel (and money!), unnecessary engine idling means harmful vehicle pollution is released into the atmosphere, which is bad for the environment and our health.

Find out more about getting your car started in the cold.