Today’s 4-stroke engines burn cleaner and run quieter than their 2-stroke counterparts. But unlike your car, the demands on a 4-stroke outboard require very special oils and oil additives. All Sierra 4-stroke outboard engine oils meet the same tough standards as the OEM engine oil and are FC-W certified by the NMMA, just like the OEM engine oils. Sierra offers many weights and blends of 4-stroke outboard engine oil to meet your particular situation. And just like every quality product that Sierra makes, our outboard engine oils are backed by Sierra’s industry leading warranty.
Available Gasoline Outboard Engine Oils – 4-Stroke
Sierra 10W-30 4 Stroke Marine Outboard Engine Oil (Premium Blend) 18-9420
10W-30 4 cycle oil is a highly refined petroleum product formulated with premium base stock and highly refined additives. Specifically formulated to meet or exceed the tough requirements of the Marine 4-Stroke motor manufacturers, Mercury, Yamaha, Johnson-Evinrude, Suzuki and Honda.
- Replacement for Mercury, Yamaha, Suzuki, and Honda
- Excellent anti-wear characteristics.
- Reduces friction.
- Formulated to offer maximum corrosion protection.
- Reduces sludge keeps engine cleaner for better efficiency.
- Low temperature viscosity offers better cold starting.
- Meets and exceeds quality performance API SJ, CF-2, CH-4• Guaranteed and backed by our famous Sierra comprehensive warranty. (Will not void your engine manufacturer’s warranty).
Sierra 10W-40 4 Stroke Marine Outboard Engine Oil (Synthetic Blend) 18-9551
10W-40 4 cycle oil is a highly refined petroleum product formulated with premium base stock and highly refined additives. A direct replacement for Suzuki motors.
- A direct replacement for Suzuki motors.
- API c-14 Plus/SL, Volvo VDS-3, Cummins CES 20078, 20077 & 20076 Certifications
Sierra 25W-40 4 Stroke Marine Outboard Engine Oil (Synthetic Blend) 18-9440
25W-40 4 cycle oil is a highly refined petroleum product formulated with premium base stock and highly refined additives.
- NMMA FC-W API SL Certified
- Formulated for 4-stroke outboard engines specifying 25w-40 oil
- Also available in other sizes click here