Would anyone be able to advise me if I can use Mobil 1, or a similar synthetic engine oil in my 1991,500SEL. The 117.965 V8 engine has 123.000 kms on it and is running as sweet as a nut at the moment. We have year round high temperatures here and wonder if the thinner, lower viscosity synthetic oil do any harm. All your $0.02's worth most welcome !