VW says to use a synthetic oil meeting the VW505/505.01 oil spec. VW says to change the oil every 10,000 miles. Cheapskate or not, using RTS at $23/gallon works out to just .23 cents per mile.
VW has noted that using dino oil will void the warranty, and they will not pay for any repairs. What...
Just take a short trip over to the TDI Club web site, and read all the stories of VW dealers using the wrong oil in TDIs. It tends to be the rule rather than the exception to use the wrong oil at some VW dealers. Always take your own oil for changes, and be safe. Better yet, do it your self.
I guess I'm just one of the bad guys by not spending every cent, and then some. A few jobs ago, I learned to put away whatever I could because it would be needed to keep the lights on between jobs. When the trucking company I was working for up and locked the doors, the savings sure came in...
What to expect? Most likely nothing. Maybe a little bit more free revving, or better throttle response. After almost 200K miles of using Red Line 5w-40 in my VW I can say that the insides are very clean. Never had any Problems with it.
An oil catch can is a device that is placed between the PCV and the intake. It takes the oil vapor in the blow-by, and "catches" it, preventing it from going into the intake where it can gunk up the intake.
Once every oil change, just dump out the dirty oil from the catch can.
It also depends on the design of the car. Audi/VW uses an oil cooler/heater that has a water jacket supplied off the water pump. The oil is either heated or cooled by the engine coolant.