I'm not sure if there's a variance on this, but the most recent story I read basically said that after you start your car, you're not supposed to wait even a minute before putting the car in drive and going.
It also mentioned people who warm their cars up are actually damaging the car, long term.
Should You Warm Up Your Car Before Driving?
A CR expert explains why letting your car idle might not be the hottest idea
It’s easy to understand the appeal of getting into a warm car when the temperature drops. Some drivers are also convinced that letting a car warm up before driving is better for the engine. But is it really a good idea?
Consumer Reports’ chief mechanic, John Ibbotson, says that giving the engine a chance to run for a minute before driving on a cold day is smart, but that there’s no need to let it run longer beyond warming the cabin and defogging the windshield. And there’s a real downside: wasting fuel and generating emissions.
An engine is fully lubricated long before it reaches full operating temperature. When your car sits for an extended period of time, the oil drains down to the bottom of the oil pan. Once you start the engine, the oil pump quickly circulates the oil throughout the motor, lubricating all the necessary moving engine components. A cold engine idles at 1,200 rpm or more, making quick work of the lubrication process. Being mindful to give your engine a chance to lubricate, along with being diligent about routine maintenance, can help most modern engines last 200,000 miles or more.
There used to be a saying about older engines that the worst thing you could do for a motor was to start it, because for a split second, those engines were somewhat dry and weren’t well lubricated with oil.
Cars have improved in technology to the point where your engine is fully lubricated within 20 to 30 seconds. By the time you get in, start the car, put on your seat belt, and get comfortable, the engine might not be fully warm. But it’s completely lubricated, and it’s okay to drive at this point.
Some drivers prefer to let the engine idle for 20 minutes or longer to get everything—including the cabin—really warm. But the fastest way to warm up an engine is by driving. Just remember not to rev the engine hard for the first few minutes. Wait until you see the temperature gauge move off the cold reading.
