30-second idling


Energy conservation experts advise shutting off the car’s engine if it is going to be idling for more than 30 seconds. That would mean shutting off and restarting at almost every stoplight. That doesn’t sound like a good idea. What do you think?


Those so-called experts do not know much about the workings of the internal combustion engine. To do what you have described would surely lead to early failure of the starter, and the replacement cost of the starter would negate the supposed savings on gas.

If you are sitting in a traffic jam, or waiting for a long train to pass, it makes sense to shut off your engine. On the other hand, to shut the engine off at every traffic light would lead to delays in traffic flow, more accidents, and possibly road rage.


I think energy conservation experts are all living on Mars. Many of the things they recommend can cause all sorts of problems like angering the drivers five and six cars back if everyone were to be starting their engines when the light turned green…and they subsequently end up with a red light. Just think of how bad the effect would be on the flow of city traffic.

Remember, these are the same guys that suggested ethanol, which as it turns out actually uses more dinosaur fuel to grow, harvest, and prcess than it saves and reduces gas mileage.

These are the same folks which are promoting flourescent bulbs…which happen to contain mercury vapor. If you break a bulb it’s a HAZMAT spill.


"The case against CFLs is built largely on half-truths and innuendo. Yes, the energy-saving bulbs contain mercury, a neurotoxin responsible for a tremendous amount of human suffering over the years. And safely recycling CFLs remains far more difficult than it should be. But these facts don’t justify sticking with inefficient incandescent technology that has barely changed since the invention of the tungsten filament nearly a century ago…

"But what about the mercury? The toxic heavy metal is integral to the design of current CFL bulbs: Electricity agitates the mercury molecules, causing them to emit ultraviolet light. That light then spurs a bulb’s phosphor coating to give off visible light. But the amount contained in each bulb is barely enough to cover the tip of a ballpoint pen, and won’t cause any bodily harm as long as simple precautions are taken. The National Electrical Manufacturers Association has voluntarily imposed a limit of 5 milligrams per bulb on all CFLs sold in the United States?about 1 percent of the mercury contained in an old home thermometer. Since manufacturers are well aware that health fears are preventing the widespread adoption of CFLs, most have committed to making bulbs with even less mercury than NEMA’s standard. The average CFL bulb now contains around 4 milligrams of mercury, and that figure should drop closer to 2 milligrams in the very near future. Much of the credit for these reductions goes to Wal-Mart, which has pressured GE, Royal Phillips, and Osram Sylvania to cut down on the quicksilver…

Ah, but what if your CFL bulb shatters? First off, don’t panic: Unless you plan on picking up the glass with bare hands and then licking it, you’re almost certainly safe from harm. Just follow the EPA’s easy cleanup guidelines, which include placing the remnants in a sealed plastic bag and washing your hands when the chore is finished, and all should be well. (Also, use common sense and don’t place CFLs where they can be damaged by young children.)…

“Even a broken CFL bulb won’t leak too much toxic metal. According to the EPA, just 6.8 percent of the mercury in a CFL bulb?that’s at most 0.34 milligrams?is released if it shatters. OSHA’s permissible exposure limit for mercury vapor in the workplace is 0.1 milligrams per cubic meter, so you’d have to break that bulb in an extremely cramped space for there to be an appreciable hazard.”

Quoted from http://www.slate.com/id/2183606/pagenum/all/#p2

Regarding the remark about Ethanol, all I have to say is BRAZIL!

Oh, and I am against shutting your car off at red lights. It won’t be practical until cars have the same technology that is used in hybrids for sutting down and automatically restarting the engine.


If we all go completely nuts, we could save money while driving to endanger and being eternally distracted. It’s not my own idea of a good idea. You want to be able to finish the trip that you start. If you have ever seen a car that quit running at a traffic light, did you wonder if it stopped running or was turned off?


That sounds like saving a dollar and risking 100. Having to constantly shift to stop and start has so many opportunities for problems it’s not worth it. Stopped at a railroad crossing for 5 minutes? Sure. But not at routine stoplights.


The people living are Mars are energy conservation “wackos”. There are plenty of real experts here on earth who know that this advise is nonsense.

I wonder if they are talking about leaving the car running while going into the convenience store for milk…

They were only looking at fuel savings.  For that they are right, but they likely did not factor any wear cost.


I think a 2 minute idle limit is more realistic.


The so called experts you refer to are impractical nuts who dispense dangerous information. Yes, I stop the engine at a railroad crossing when the train has 130 or so cars, and when in a gridlock traffic jam.

There are a number of cars built in Japan that have an auto engine shutoff, to conserve fuel and keep the air clean. But the shutoff timing is more much than 30 seconds, and the feature has an override.

In the morning in most weather, you do not need to idle the car more than 30 seconds before driving off, provided you can see out of the car.

A few years ago, a local electric utility had some useful tips for saving electricity. One was letting hot food sit on the kitchen counter till it reaches room temperature before putting it in the fridge!!! This tip was submitted by one of their electrical engineers, and not their home economist! They had a storm of emails and phone calls from irate housewives.