[image found on Carbon Offset Solutions]
Don’t ask me where I heard this, but for my entire life I believed that starting a car used up the same amount of fuel as an idling car used in five minutes. So for as long as I’ve been driving (which is inching up on two decades now), I thought the “smart” thing was to leave the car idling for a few minutes rather than turning it off. Turns out I was completely and totally wrong according to this article. Idling for 10 seconds uses the same amount of fuel as starting a car in the first place. Idling a car for 10 minutes can use as much fuel as it takes to travel 5 miles. And even on the coldest days, idling your car for 30 seconds is all you need before driving away – the car will warm up faster on the move rather than idling (though the article says not to accelerate hard or drive at high speeds for the first 3-5 miles…which isn’t exactly practical advice in all situations).
I’m generally one of those types of people that thinks he’s right most of the time, but I try to keep myself open to correction and further learning…and I’ve just been schooled on the issue of idling.