What type of motor oil should you use in your 1987 Mercedes Benz 420 Sel?

For a 1987 Mercedes Benz 420 SEL, it's recommended to use a high-quality synthetic or conventional motor oil with a viscosity of 10W-40 or 15W-40, depending on the climate and driving conditions. Look for oils that meet or exceed API specifications, ideally those labeled for use in older vehicles. Always consult the owner's manual for specific recommendations and to ensure optimal performance and engine protection.