Owners' Manuals

Many vehicle owners' manuals have specific instruction on idling requirements along with recommendations and warnings to avoid excessive idling for reasons of fuel economy, severe duty that results in engine wear and oil breakdown, when the vehicle is unattended, and most importantly - the danger of idling in enclosed spaces or when ventilation is not adequate, as deadly carbon monoxide poisoning can occur.

NOTE: It's a myth that idling is good for an engine or doesn't cause additional wear. Excessive idling can create engine wear and carbon soot buildup in the engine and components, and affect the life of engine oil. It can also shorten the life of spark plugs and the exhaust system due to condensation build-up.

As engine technology evolves, a growing number of owners' manuals do not mention idling as these vehicles rarely idle (stop start or hybrids) or not at all (pure electric).

Below are samplings of manufacturer's original owner's manual pages for a variety of makes and models from 2016-2009 (red outlines and yellow highlights added).

In addition, the Oak Ridge National Laboratory (ORNL) conducted the study: Summary of OEM Idling Recommendations from Vehicle Owner’s Manuals