This post is by Mel Peffers, Air Quality Project Manager at Environmental Defense.
Many people idle their car engine in winter because they think it needs time to warm up. Not true! Today’s fuel-injected engines don’t need a warm-up period, and idling for long periods can lead to excessive engine wear.
Worse, cars idling for over 10 seconds use more gas and create more global warming pollution than simply restarting the engine. Surprised? It’s true. The 10-second rule has been proven empirically.