When temperatures slide toward zero and below, as they are forecast to do this week, motorists may be tempted to let their vehicles warm up before hitting the road. But the American Automobile Association (AAA) says it isn’t necessary, and police warn that it’s risky.

Vehicles running and left unattended are prime targets for thieves, as shown by a spike in auto thefts in Minneapolis last year. And while those first few minutes shivering in a cold car can be downright miserable, waiting a few minutes for the engine to warm up and the heat to kick in won’t improve performance, said David Bennett, AAA’s repair systems manager.

“The driver should start the engine and allow it to idle only for the time it takes to fasten their seat belt,” he said. “This ensures that lubricating oil gets to all of the engine’s vital parts. Driving the car normally and avoiding hard acceleration brings the engine to a warmer temperature faster and also reduces wear and exhaust emissions.”

It’s fine in winter for drivers to let vehicles run a few minutes while they clear snow and ice from the windshield and other areas of the car, Bennett said.

But on that point, here’s a reminder that in Minneapolis it’s illegal to let a car idle for more than three minutes in a one-hour period, or for more than 15 consecutive minutes in any one-hour period when temperatures are at zero or below.

Under no circumstances should drivers step away from their running or unlocked vehicles without taking their keys or fobs with them, said Jim Schweitzer, chief operating officer of the National Insurance Crime Bureau (NIBC).

Forget to take them and your wheels could be gone in an instant, said Garrett Parten, a spokesman for the Minneapolis Police Department.

“Hot-wiring is almost impossible,” Parten said. “It’s pretty difficult to steal a car without a key.”

But with access to a key or fob, it’s pretty easy. With advanced technology, many car models can be started with the push of a button if a key or fob is inside. An idling or unlocked car with a key inside is a golden invitation for thieves to drive off with a vehicle that isn’t theirs.

“It’s a crime of opportunity,” Parten said.

That was the case last Thursday. A man left his car running with two kids under 3 years old in the back seat while he went inside a Minneapolis school to pick up another child. He was away for only a minute, but his car was gone when he came back. Police found it abandoned a few blocks away with the kids inside, unharmed, Parten said.

Last year, crooks in Minneapolis swiped more 2,870 vehicles, a five-year high. In the city’s North Loop neighborhood, vehicle thefts jumped 150% last year. One of the biggest reasons was that in about half the cases, thieves had access to a key or fob.

The NICB found that 81,911 vehicles — 11% of all vehicles stolen in the United States in 2018 — had the keys or fobs inside. And the number might even be higher, the bureau said.

“We are creatures of comfort and say, ‘I will be quick. I’m just going into the gas station, the office or the house and I’ll be right back,’ ” Parten said. “It’s frustrating that you have to lock your doors [and take keys with you], but that is the unfortunate reality. There are bad people running around doing bad things. They don’t care about you or your things.”

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