Here is the opening section of an article I saved a couple of years ago but can't currently find online. Good source and it addresses everything being discussed in this thread. Summary: 1. In modern engines, no need for prolonged cold warm-up 2. Long periods of warm idling do no harm (to the engine, anyway).
No link as it seems to have disappeared. Take it FWIW.
It’s another gray, Utah winter morning. The inversion is thick. The air is damp. And it’s cold. Not as if this is anything new. You dive into your normal pre-work routine, finish breakfast, and head out to start the car before heading back inside to brush your teeth. One last glance in the mirror, give the dog a treat and head out the door … to find your car stolen.
Far from a far-fetched start to another winter day, unattended idling cars are a regular sight in most neighborhoods on winter mornings. Drivers might think they are doing their cars good. But what are they doing to the air? Thickening our inversion with pollution. What are they doing to the neighbor’s kids? Increasing the likelihood of asthma attacks in children. What are they doing to your insurance rates? Increasing them. What are they doing to the earth? Just warming it up a bit.
Outside of Salt Lake City, more communities are beginning to take steps to reduce the time vehicles spend idling. For police and insurance companies, these efforts are driven by a desire to reduce auto thefts. For environmentalists, the urgency to slow global warming is all encompassing. For health-care workers, the link between the pollution that comes from our tailpipes and a list of health woes is inescapable. So join us for a primer on the perils of stationary, smoking autos.
Idle Worship
Many people are adamant that their car engine will be damaged if they head out on a cold morning and don’t spend several minutes idling. But let’s ditch the opinion of the guy at the local garage and head directly to an expert. Here’s a question and answer session with Mike Vaughn, who was public affairs manager of Global Technology for Ford Motor Company in Detroit, Mich.
Q: Is there benefit in idling your car to warm up the engine?
A: Not really. The engine is most efficient after it reaches optimal operation temperatures, but it reaches those temperatures much faster through gentle driving. And your transmission, tires, wheel bearings, steering and suspension need to warm up, too. That only happens by driving the car.
Q: Is there harm done to the engine by prolonged idling?
A: We’ve had test engines idling for thousands of hours without significant changes. I’m not sure I have seen anything to back up the idea that excessive idling causes buildup in cylinders or fouls plugs.
Q: So no harm, but no help. Pretty much you should start your car and go?
A: Yes. Modern gasoline vehicles are designed to start up and drive. Start your car, put on your seatbelt, lock the doors, perhaps play with the radio dial and it is time to go. Drive the car gently until the temperature gauge shows movement. For most of us, that will take just a few blocks. I guess if you live on a highway onramp, there is benefit in idling. But I don’t know of many people who live on the highway onramp. Idling mostly just lowers your fuel economy. It is one reason most people’s average miles per gallon drop in the winter.
Q: What about idling at the drive through or convenience store? Do repeated starts wear out the starter or other parts?
A: Your modern car is designed to withstand hundreds of thousands of starts without unusual wear on any part. I wouldn’t worry about your starter.
Q: Why do you think so many people continue to idle their cars on cold mornings?
A: Some of it might come from what they learned from their fathers, based on older cars that needed a warm-up period. But that is not the case with new cars. But really, I think most of it comes from wanting the inside of the car warm. People just don’t want to be cold for the few minutes it takes for the engine to reach operating temperatures and the heater to warm up the passenger compartment. They will tell you it is to warm up the engine, but really it is to warm up themselves.
Q: You live in Michigan, and I know it gets pretty cold there in the winter. Do you idle your car?
A: Nope, I have seat heaters—a great invention.
Stop and give me 10
According to tips found on the Utah Department of Environmental Quality Website, the quicker you are to kill the engine, the better. Ten seconds of idling uses more fuel than restarting the engine.
Radio, radio
You pull into the office parking lot and just can’t bear to leave before hearing the last of Rush Limbaugh’s lecture. Or maybe the day will be a wreck if you don’t hear the final four minutes of “Stairway to Heaven.” Surely, then, it’s alright to keep the car running to indulge your aural fix? Nope. Your car battery can handle this one just fine. No need to waste all that gas. Using just the radio, your car battery draws about a half amp of current per hour. If you listened for 24 hours, you’d use only about 20 percent of the battery’s power. And then you’d be really late for work.
Up in smoke
“So what if my car doesn’t benefit from idling. What harm am I doing?”
Here’s what chugs forth from your tailpipe: carbon monoxide, nitrogen oxides, suspended particles and volatile organic compounds. Nitrogen oxides and volatile organic compounds are the two main substances involved in the formation of ozone, a component of smog. Ozone and suspended particles are included in the group of chemicals associated with significant respiratory health effects and hospital admissions.
The city of Toronto, one of North America’s most aggressive foes of idling autos, estimates that if every driver in the city avoided five minutes of idling per day, the city could shed 79 tons of carbon dioxide every day from its atmosphere. Toronto residents could also avoid wasting a collective 8,700 gallons of gas per day, a savings of more than $25,800 in Canadian dollars. That’s for one city, one day. Now imagine the cumulative effects over the course of one year.
Closer to Utah, Logan received unwelcome attention when it was reported during the winter of 2004 that the lovely Cache Valley contained the nation’s dirtiest air. Subsequent stories challenged the monitoring as flawed, and Logan came away saying that its air was indeed bad, but not quite as bad as first thought. But at the time, Logan’s drastically unhealthy air called for drastic measures. Drivers were asked to cease idling their cars. Drive-thrus were shut down.
Diesel emissions contain toxic chemicals increasing the risk of asthma, lung and heart disease and are responsible for as many as 125,000 cancers nationwide. Dr. John Wargo of Yale University reported that students on school buses are exposed to 5 to 15 times the levels of particulate pollution than at nearby monitoring sites. The United Sates’ EPA has determined that diesel fumes contain 40 toxic chemicals, including 15 carcinogens.
Stay away from the tailpipe
Auto exhaust is thought to be the leading cause of accidental carbon-monoxide poisoning in North America. Cars idling in the garage, even with the garage door open, are pumping deadly carbon monoxide into the house. The gas becomes trapped in the garage and can easily disperse through the house’s framing joints, door jambs and ductwork seams.
Tracking accidental carbon monoxide deaths from auto exhaust in the barest of “just the facts, ma’am” style is the National Highway Transportation Safety Administration. It lists more than 160 such deaths from its collection of 1998 death certificates. But even the barest of facts present an ugly picture. In one incident, eight people, including four kids 10 years of age or younger, died when two adults left their truck running in the garage so they could listen to the radio. The carbon monoxide killed them all.
(Edited to restore what was clipped in the board software update)