Overview of Bel-Ray MC-4T 20W-50 Mineral Engine Oil Protect your engine with Bel-Ray MC-4T 20W-50 Mineral Engine Oil (99405-BT1LA), a premium petroleum-based oil for 4-stroke motorcycles and ATVs. This multi-grade 20W-50 oil reduces wear and oil consumption, ideal for air- or liquid-cooled engines with wet clutches, ensuring smooth shifts.