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	Idling Myths
	There are myths surrounding the benefits of idling an engine; such as allowing the engine to warm up in cold weather.  However, the Environmental Protection Agency Clean School Bus USA lists a set of facts to counter the myths.  Head Start and other Early Childcare Administrators may use these tips to as a training tool for bus operators.     Myth: It's important to warm up the engine with a long idle period, especially in cold weather. Fact: With today's school bus engines, bus and engine manufacturers routinely suggest a warm up time of less than five minutes. In fact, running an engine at low speed (idling) causes significantly more wear on internal parts compared to driving at regular speeds. Myth: It's better for an engine to run at low speed (idling) than to run at regular speeds. Fact: Running an engine at low speed causes twice the wear on internal parts compared to driving at regular speeds. Myth: The engine must be kept running in order to operate the school bus safety equipment (flashing lights, stop sign). It's impossible to run this equipment off the internal circuitry of the bus because the battery will run down. Fact: Safety equipment can be operated without the engine running through re-wired circuitry for up to an hour with no ill-effects on the electrical system of the bus. Myth: Idling is necessary to keep the cabin comfortable. Fact: Depending on the weather, many buses will maintain a comfortable interior temperature for a while without idling. Idling is also not an efficient way to keep the cabin warm. Bus routes should be timed so children and drivers do not need to spend a lot of extra time on the bus when it is not en route, particularly in hot or cold weather. In addition, auxiliary heaters can be purchased and installed to keep the cabin comfortable. Myth: It's better to just leave the engine idling because a "cold start" produces more pollution. Fact: A recent EPA study found that the emission pulse measured after the school bus is restarted contains less carbon monoxide, nitrogen oxides, and other pollutants than if the school bus idled continuously over a 10-minute period. The analysis indicated that continuous idling for more than three minutes emitted more fine particle (soot) emissions than at restart. Idling Myths. Clean School Bus USA. EPA/OTAQ. 2007. English.