My Dad and I were talking about his 1989 Mercedes 560SL with the V8 in it. It sits down here in Scottsdale AZ for about 6 months out of the year. During his time here he puts about 2000 miles on the car. His mechanic recommended he use full synthetic. Currently he changes it about once a year. Short trips... Can someone recommend some oils. Currently 5w-30 dino is in the car. The car has 60,000 miles on it. Is there really a need for synthetic? My inclination is to say change it once a year with any quality oil and worry about other things.... Any suggestions would be welcome.