Last month I changed the oil and filter on our recently acquired 1995 E420. The manual calls for 8 1/2 quarts of oil with the filter change and that is what we put in. When I checked the oil after the car was in our garage over night, the reading was half way between the minimum and maximum mark. My conclusion was that Mercedes allowed for a quart variation, plus or minus, before they felt anything was out of spec. Since 8 1/2 quarts is what the manual says that is what I am going to follow.