What type of oil goes into a 2001 Volkswagen Passat?

Answer 1

By weather he or she means that the thicker oil holds up better under high temperature (which it does), increases oil pressure and reduces oil consumption in high mileage engines. But straight 30W and 40W oils are too thick for cold weather and may make an engine hard to start. They may also be too thick to provide adequate start-up lubrication to critical upper valvetrain components during cold weather. So switching to a straight 20W oil would be necessary for cold weather driving. Straight 10W oil can also improve cold starting, but is very thin and should only be used in sub-zero climates. A multiviscosity 10W-30 or 10W-40 will provide the same cold starting benefits of a 10W oil and the high temperature protection of a 30W or 40W oil. (copied from: http://autos.yahoo.com/maintain/repairqa/air_filters_oil/ques120_1.html)

5w-20 or 5w-30 depending on the weather environment