Idling engines definitely waste fuel, needlessly pollute and contribute to climate change by spewing carbon dioxide into the atmosphere, but there are other considerations.
The only way an engine can achieve an efficient operating temperature is to be driven. At idle, temperatures are too cool to combust efficiently. The incomplete combustion leads to condensates containing carbon and other pollutants collecting on the cylinder walls. These condensates are washed past the piston rings and into the engine oil. The pollutants dilute and contaminate the oil reducing its lubricating qualities.
Diluted oil isn’t as efficient at protecting bearings, cylinder walls or piston rings and these parts wear out faster. So by not idling unnecessarily you can extend the life of your engine and oil and filter. As a professional mechanic I witnessed this first hand. Laboratory analysis of engine oil samples showed marked improvement of oil quality when idling was eliminated, to the point of more than doubling the oil and filter change cycle. So it is even quantifiable and the savings were substantial.
The second consideration of idling is air quality. As noted idling engines are burning inefficiently. The emissions equipment that vehicle engines depend on require heat to operate efficiently. A cool catalytic converter isn’t functioning, so the dirty unburnt fuel released from an idling engine finds its way out the tail pipe and into our lungs and the lungs of our children, pets, wildlife and even our garden foods.
Studies have shown the worst place to idle is where people congregate, like at bus stops, schools or near your homes. The contaminants in idling exhaust are proven carcinogens and contribute to respiratory and cardiovascular disease. Children and the elderly are particularly vulnerable.
So by not idling unnecessarily you can reduce your carbon footprint, extend the life of your engine, improve air quality and the health of our community and save money! You can’t you go wrong.
So if you’ll be stopped for more than 30 seconds, turn off your engine because idling gets you nowhere, man!