5W-30 ( according to the Owner Guide )
SAE 50 is a single weight oil that is 50 weight when cold or hot. SAE 20w50 is a multi-grade oil. When cold it flows as a 20 weight oil and therefore flows much easier. At full operating temperature it flows as a 50 weight oil. The W stands for winter.
20w 50
Most people swear by rotella t brand. weight can be 10w-40, 10w-50, or most common is 15w-40
Slick 50 can be used with any weight of oil. We have used it for years, and a very good product.Im however not to sure about the synthetic oils if you are using them.
20/50
25w50 or 50 depending on your climate
20/50
straight 50
I'm Not sure what the factory recommends but we run 800cc's of 50 weight in our race bike.
It will take 2 1/2 to 3 qt. if it is above 60 degrees most of the time in your area used straight 50 weight.
97 VW Cabrio calls for 5W-50 oil. It is hard to find in this weight unless you go with synthetic. Synthetic oil could be expensive, so you might want to come as close to 5W-50 as possible. Possibly 20W-50 if its not in the winter.
Possibly. Crawl under the car and look. They will be locted on the oil pan.