What is the oil capacity for a 1991 Mercedes 500SL?

The oil capacity is around 8.5 qts. of oil. If you're replacing the oil filter, it will take another 1/2 qt....maybe a dash more. When you go to buy the oil, you can have the counter man at the store look up the exact amount of oil you'll be needing. Depending on your mileage, Mobil 1 is recommended. If you have more than 80,000 miles on the engine, you might want to consider a 10-40 natural oil. Remember, synthetic oil costs about 3 times as much as regular oil, but lasts longer...again...a high mileage engine might burn through it, and not be recommended. You can call your local MB dealer and ask them what oil they suggest for your car...they're happy to help you on these things.