Should You Idle Your Car or Truck in the Winter?

The research is in, and the results are consistent: It's a waste of time and money to “warm up” your auto in wintry weather before starting to drive. This unwise practice creates unnecessary pollution.

Experts ranging from the U.S. EPA to the government of Canada and famous radio talk show mechanics agree - warming up your vehicle's engine in the driveway has virtually no benefit for your engine. On occasion, letting the engine run can help defrost your car a little, but even then, actually driving the car is the most efficient way to up the engine's temperature.

Regardless, a study of about 1,300 Americans found that on average, people believe that vehicles ought to be idled for about five minutes when the weather is wintry. The results of that belief are as follows:

  • For each automobile, $9 per year in unnecessary wear-and-tear costs
  • Increased personal exposure to pollutants while sitting in stopped autos
  • Nationally, 40,000 tons per day of unnecessary CO2 released into the environment
  • Throughout the U.S., $5.9 billion per year in wasted fuel
  • For each car “warmed up”, $30-$183 annually in wasted fuel

The foundations of the myth that cars need to be idled to warm up are based on a time when it was true. Before the advent of electronics in the starting and fuel delivery systems, cars and trucks used carburetors to mix air and fuel for the engine to use. If a car was driven cold, that mixture could be off and make the engine stall. Almost all new cars have updated technology. As well as conserving gas when you turn the ignition, electronics monitor engine temperature. Now, it is widely agreed by experts that you should idle your engine for no longer than 10 seconds before starting to drive.

If you stop idling, there will be many beneficial effects. First, your vehicle will work better and heat up faster. A car or truck that is on the road also begins the process of filtering the tailpipe air more quickly by way of the catalytic converter. When you are stopped, the catalytic converter doesn't start working for about twice as long, and the dirtier air invariably gets to you because, of course, you're not going anywhere.

If you have concerns about this or want to find out whether your automobile needs to be warmed up, contact the auto professionals at Christian Brothers Corpus Cristi. Not idling saves time and is better for your auto, good for the environment and better for your wallet.