Some will warm the car for about 10 mins.or longer before leaving. Other will leave before car is throwing heat. Which is correct?
Both depending on the situation they are.
Lets suppose it is 10 degrees outside. You are getting ready to take your 6 month old baby to the sitters so you can go get your tags renewed. You might want to let the vehicle warm up for the safety of the child. Now lets go further. Lets say the car is setting outside and the windows are covered in icy snow. It will take the car warming up and defrosting the windshield before you can safely see while operating the vehicle.
There is two sides to most stories. So we will also look at a sunny 70 degree day and no passengers. No need to warm the vehicle. Get in it and go. The vehicle has many sensors that are designed to do all the work.
As far as the vehicle is concerned, the manufacturer does not suggest that you allow it to warm up before driving. It has no effect on the warranty either.