SENGAIKI 4T 25W-40 API SL Recommended for lubrication of the latest 4-stroke outboard and inboard motors (Mercury, Yamaha, etc.). These applications are commonly referred to as “inboard and inboard motors.” It can also be used for 4-stroke outboard motors. Is a mineral-based 4-stroke outboard engine oil with NMMA approved for use in particularly harsh marine environments. Ratings that set minimum standards for outboard motor lubrication, corrosion protection, and resistance to the potentially harmful effects of fuelinduced oil dilution are important for outboard motor oil to meet minimum values. We provide a warranty.