Warming up the engine is a technique that your father has thought you, and he was right. But for old cars only, like 20 years and above. The cars that are produced in the last two decades don’t need warming up at all, so running it idle for five minutes is just a waste of time. Not just time actually, you are wasting gas and you pollute the environment too, unnecessarily. So tell your dad to warm up his car, yours doesn’t need it at all.
Warming up the engine before driving could be good for your car if it is literally freezing outside. Otherwise it is not needed. Also it is a choice if you want to warm it up so that the heat will come inside and the drive will be more comfortable, or if you need to clear the windshields from the fog that is created by the cold weather.
Warming up and revving the engine at idle can be harmful for the new cars, with driving it the car will warm up much faster than idle.
Here we have some very good tips for you, if you need to clear the windshield In the winter days, and they work really good and really fast. Check it out: DEFROSTING THE WINDSHIELD TIPS!