This week in Climate Connection, we’re going to tackle a topic that often elicits strong and fiercely held opinions. The topic is engine idling, and lots of us firmly believe that a vehicle’s engine should be warm before driving, especially in cold weather, that stopping and starting the engine is bad for it and/or the starter, and that idling doesn’t burn much fuel, or cause much harm to the environment.
We’d best go straight to the experts on this one: Click and Clack, the tappet brothers, aka Tom and Ray of Car Talk.
John who manages an RV park asks: Why does everyone who has a diesel start and idle it for 30 minutes before leaving?”
Tom: Because they’re inconsiderate knuckleheads, that’s why.
My, this subject does elicit strong opinions! Tom goes on to say (in a more civil tone): In all weather but extreme cold, most diesel-engine manufacturers recommend idling the engine for 10 to 15 seconds before driving away gently. That’s SECONDS! For extreme cold, up to 30 seconds may be helpful.
Ray: Even if someone left his or her lights on, or otherwise drained the battery, it’s still better for the engine to drive the vehicle for an hour than to let it idle for an hour.
Tom: Cummins, for instance (one of the major diesel engine manufacturers), warns in its owner’s manuals that excessive idling of the engine can cause carbon to build up on the pistons, piston rings, injector tips, valves and more. Which leads to expensive repairs and shortens the life of the engine.
Ray: So, not only is it not necessary, it’s actually harmful! (They do point out that some diesel engines with turbo-chargers call for three to five minutes of idling before shutting down, to allow the turbo to cool off.)
Due to space considerations and to avoid further insult, however good-natured, from our Car Talk experts, here are a few more quick facts on the topic of idling, for both gas and diesel engines, and practical reasons to limit it to a minimum: It’s expensive, cars burn up to half a gallon an hour and medium duty trucks burn even more at idle — at Sitka’s average gas price of $4 plus, that adds up. Each gallon burned releases 20lbs of the greenhouse gas, carbon dioxide, into the atmosphere, and tail pipe emissions contribute to the formation of ground level ozone, which can damage lungs. Millions of new asthma cases in children every year are ascribed to vehicle emissions. Idling for more than 10 seconds uses more fuel than stopping or restarting; frequent stopping and starting of engines doesn’t hurt the engine or the starter in all but the oldest models on the road today.
For more input from Tom and Ray on this subject, or for any other automotive question you have, visit https://www.cartalk.com/blogs/tom-ray/idling-inconsiderate-knuckleheads; for more tips on reducing vehicle emissions, visit https://www.epa.gov.
Barbara Bingham,
Citizens’ Climate Lobby, Sitka Chapter