Is it better to idle, or stop and restart my car?
It is generally better to stop and restart your car if you're idling for less than 10 seconds because idling uses more fuel and emits more CO2 than an engine restarting.
Which Is Greener: Idle, or Stop and Restart?
Don't I need to idle my car for a while to warm it up?
A vehicle warms up faster when driving than it does when idling, and most modern car manufacturers recommend avoiding idling and driving off gently after running the vehicle for about 30 seconds.
Idling Reduction for Personal Vehicles
Is vehicle idling dangerous?
Depending on the type of fuel used by a vehicle, vehicle idling can release particulate matter, carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons into the air we breathe. For diesel vehicles, diesel exhaust or soot can get lodged deep in the lung and potentially cause adverse health effects. The Environmental Protection Agency (EPA) has classified diesel exhaust to be 'likely to be carcinogenic to humans by inhalation' for long term exposure.
EPA Health Assessment Document For Diesel Engine Exhaust
Diesel Exhaust and Cancer