Idling myths and truths
Myth: Turning the engine on and off wears it out.
This is not the case in modern cars; electronic ignitions have eliminated this problem.
Myth: Idling reduces wear and tear on the engine, particularly when cold.
Idling creates wear and tear on your engine because fuel does not combust completely, causing damage to engine components such as cylinders, piston rings and the exhaust system.
Myth: The engine needs to stay on to keep the battery fully charged.
Batteries have evolved. Modern batteries now need far less running time to retain their charge.
Myth: Idling is needed to keep the catalytic converter hot and working properly.
Catalytic convertors do need to be warm, but an idling engine does not achieve this. The catalytic convertor will retain its heat for over 20 minutes after the engine is switched off.
Myth: Starting an engine uses more fuel and produces more pollution than idling.
Idling for more than ten seconds wastes more of your fuel (and causes more pollution) than stopping and restarting your engine does. This is one of the reasons why newer vehicles are fitted with stop-start technology.
Myth: The best way to warm up a vehicle is to leave the engine running for a few minutes.
Modern engines do not need a lead in time to warm up before use, they are designed so that you can commence driving straight after starting the car.
Myth: When it's cold you need to keep the engine running to keep the car and passengers warm.
The car engine will stay warm for over half an hour. To maintain heat through the fans you can turn the engine off but keep the ignition on.