Oil viscosity--seems we've seen the topic before. My own practice has been just to RTFM and do what it says; I assume that the MB engineers knew more about the topic than I do. The Benz does well (at 166k miles) on the 20-50 that the manual suggests, and the Saab on the lighter oil that's specified for it.

__________________
Craig Bethune

'97 SL500, 40th anniversary edition

'04 Olds Bravada (SWMBO's)
'06 Lexus ES330
'89 560SL (sold)


SL--Anything else is just a Mercedes.
(Kudos to whoever said it first)