Leaving a car running unattended is illegal in Colorado, and you could be ticketed.

You’ve been warned.

It’s days like this that are the most tempting to go start your car on and run back inside while waiting for the interior to get all toasty before driving anywhere. But it wastes gas, it could get your car stolen, and is against Colorado law.

Colorado Revised Statute 42-14-105: The owner or operator of a covered vehicle shall not cause or permit the vehicle to idle for more than five minutes within any sixty-minute period except as authorized by subsection (2) of this section...(k)  When idling for up to twenty minutes in any sixty-minute period if the ambient temperature is less then ten degrees.

It’s called “puffing,” when drivers start their car and then leave it unattended while running.  Leaving your keys in your car while running is pretty much like putting a big sign that says “steal me” in your back window.

According to The Examiner:

  • 50 percent of all stolen cars have the keys inside.
  • 40 percent of Colorado residents have left their car running unattended at some point.
  • 35 percent of Colorado residents were unaware that “puffing” was illegal.
  • 40 percent of Colorado residents know someone whose car was stolen.
  • Cars are most often stolen for parts, not the entire vehicle.

A lot of people equate warming their car up to stretching their body in the morning. They think their car needs to sit there and idle to get its engine ready for a big drive, but it's just not true. According to Mother Earth News most people waste a lot of gas warming up their cars for no reason.

The vast majority of cars on the road today use electronic fuel injection. When your car’s engine is cold, the computer tells the fuel injectors to stay open longer, allowing more fuel into the engine to help it run cold. As the engine warms up, the injectors let in less fuel and everything returns to normal, so to speak.

They say the best thing to do for your car on a cold day is to start it, let it run for 30 to 60 seconds (to get all the fluids moving) and start driving “gently”. This will get our engine to “warm up” faster, get your heater heating faster, and use less gas. (Although they do say to give your car a few extra minutes of warm up time in sub-zero temperatures.)

These claims are also made by MSN Autos.

Remember the reply your dad gave you as a kid when you asked him to turn up the thermostat? His answer of "put on a sweater" is the same thing you should tell yourself when you're tempted to let your car idle until the cabin is warm and toasty.

Warming up your car more than a minute or two doesn't help your car at all. It spews more exhaust into the air and uses more gas and leaving it unattended put out an open invitation for car thieves.

Put on an extra sweater and remember this moment when you're complaining about the heat in July.

Oh, and puffing on public streets is illegal. Do I need to mention that again?

Check out the website for  Coloradans Against Auto Theft who are behind one of the big anti-puffing ad campaigns.

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