What kind of antifreeze for 420 sel Mercedes?

For a 1991 Mercedes-Benz 420 SEL, it's recommended to use a high-quality ethylene glycol-based antifreeze that meets the specifications outlined in the owner's manual. Look for a coolant that is phosphate-free and specifically designed for Mercedes vehicles, such as MB 325.0 approved coolant. Mixing different types of antifreeze should be avoided, so it's best to use the same type that is already in the system or completely flush the system before switching.