Green Buckeye

Over and over on green web sites and blogs I've read that one way to reduce greenhouse gases (GHGs) and save money is to stop idling. They urge me to shut down my engine if I'm going to be stopped for more than 10 seconds, 30 seconds, 2 minutes, 10 minutes - none of them seem to agree on how long.

Frankly, I was skeptical. Even though I know that, "When you're not moving, you're getting zero miles per gallon," wasn't there some mitigating reason not to turn off the engine? Doesn't the engine need to be warmed up? What about the amount of gas it takes to start the engine - isn't that more than when the engine is running? What about the wear and tear on the engine with all that on and off? After all, I don't want to save a few pennies or emissions only to have to replace my engine early.

I decided to research a little more. Here's what I found.

Car Talk

• In Driving Tips for Treehuggers, Click and Clack reassured me that "Except in below-zero conditions, you can just start the engine and drive off." Unless I'm scraping ice off the windshield, looks like I'll be turning the key and driving off. Some of the other sources indicated that cars needed no more than 30 seconds of warm-up idling.

Edmunds

• I figured they would be the most mainstream and skeptical. Guess what? In What Really Saves Gas? And How Much? the Edmunds folks said you could improve fuel economy by as much as 19% by avoiding excessive idling. Their recommendation? Shut it down if you're stopping for more than a minute. This was the longest amount of time recommended by any of the media sources, which I would expect given their love of car culture.

California Consumer Energy Center

• This page busts several myths, and comes to the conclusion that "more than ten seconds of idling uses more fuel than restarting the engine." They also say that "component wear caused by restarting the engine is estimated to add $10 per year to the cost of driving," which they think will be recovered from the savings from not idling. According to this source then, I can go ahead and shut the engine off if I'm stopping for 10 seconds or longer, and I don't worry about the wear and tear. The Canada Office of Energy Efficiency backs this up, too.

So here are Tina's Green Buckeye guidelines for idling:

• Unless it's below zero, start the car and drive off. The most conservative recommendation for warming up the car is 30 seconds, so if you can't get out of the habit completely, warm up for 30 seconds.
• Except in traffic, if you're going to be stopped for more than 10 seconds, shut off the car. You'll save money and greenhouse gases. You can take the Edmunds conservative recommendation of one minute, but you won't save as much.
• Park the car and walk into the fast-food joint or bank instead of using the drive-thru. It's better for you, it's better for your mileage, and it's better for the planet!

Labels: consumer choices, environment, tips, transportation