it just takes a minute or two for the oil to circulate. obviously oil goes down to the oil pan when the car is off. so it has to travel from the pan to the head which will take some time. nothing to really worry about. the sales people just try to sound smarter than they really are. FYI 60% of engine damage is from letting your car warm up in winter. with that said, my car has 154,xxx on it and I let it warm up for 5 minutes every morning prior to getting in it. starts every time, doesnt burn or leak anything.