My Dad had his first car in the '60s, and many of his beliefs about cars and car maintenance stem from cars of that era. He was adamant about two rules he said would extend the life of my car:
1. Warm up the car for at least two minutes when you start it.
2. The process of starting your car is incredibly hard on it -- leave it running if you'll be idling for less than 5 minutes.
And being the dutiful daughter that I am (most of the time), I've followed his advice for the past 20 years. But yesterday I learned that (gasp!) he's wrong about both rules... or at least those rules do not apply to modern cars.
According to the California Energy Commission's site, if you'll be idling for more than 10 seconds, it's better for the environment and for your car to turn it off. I recommend that you read the full article, but here are some highlights:
- For every two minutes a car is idling, it uses about the same amount of fuel it takes to go about one mile.... But you're not going anywhere. Idling gets ZERO miles per gallon.
- Ten seconds of idling can use more fuel than turning off the engine and restarting it.
- With today's modern engines, you need no more than 30 seconds of idling on winter days before driving away. [Note that they say WINTER days. I'm sure a few seconds will suffice during the summer.]
- Excessive idling can actually damage your engine components, including cylinders, spark plugs, and exhaust systems. Fuel is only partially combusted when idling because an engine does not operate at its peak temperature. This leads to the build up of fuel residues on cylinder walls that can damage engine components and increase fuel consumption.
- Frequent restarting has little impact on engine components like the battery and the starter motor. Component wear caused by restarting the engine is estimated to add $10 per year to the cost of driving, money that will likely be recovered several times over in fuel savings from reduced idling.
I gave this "no idling" rule a try yesterday: I waited to turn on the car until I was ready to drive away (kids settled, seatbelts on, iPod playing, sunglasses on); I turned off the car when I got to the station to pick up my husband even though I could see the train coming in; and later, I waited to start the car until the other traffic had passed and I could leave my parking spot. It'll take me a while to get used to this way of thinking (I forgot to turn off the car when I hit red lights, for example), but this seems doable.