{"product_id":"sierra-18-9690-10w-30-fc-w-full-synthetic-marine-engine-oil-available-in-quart-and-gallon","title":"Sierra 10W-30 Full Synthetic Marine Engine Oil - Available in Quart and Gallon Sizes","description":"\u003cp\u003eSierra 10W-30 Full Synthetic Marine Engine Oil is a special blend of synthetic base oil and a balanced additive system engineered specifically for 4-stroke outboard and sterndrive engines. The formula exceeds FC-W requirements and is NMMA FC-W Certified as well as API-SL rated, making it suitable across outboard and sterndrive applications alike.\u003c\/p\u003e\u003cp\u003eThe synthetic base stock delivers faster lubrication at startup in low temperatures, so critical engine components get protected oil flow sooner on cold mornings. At the other end of the temperature range, the formula holds up under high heat, maintaining film strength and protection during sustained running. A balanced additive package gives the oil greater resistance to oxidation, which translates to lower oil consumption over the service interval and more consistent protection between changes.\u003c\/p\u003e\u003cp\u003eThis oil is offered as a single product line across two container sizes so boat owners can buy the right quantity for their engine's oil capacity and change interval. The Quart size (946 ml) suits smaller top-offs or engines with lower oil capacities, while the Gallon size is a more economical option for full oil changes or engines that require larger fill volumes. Both sizes contain the same 10W-30 full synthetic formulation.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-9690\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e 10W-30 Full Synthetic Marine Engine Oil\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eViscosity Grade:\u003c\/strong\u003e 10W-30\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCertification:\u003c\/strong\u003e NMMA FC-W Certified, API-SL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRecommended Use:\u003c\/strong\u003e 4-stroke outboard and sterndrive engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContainer Type:\u003c\/strong\u003e Bottle\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAvailable Sizes:\u003c\/strong\u003e 1 Quart (946 ml), 1 Gallon\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC (Quart):\u003c\/strong\u003e 808282184353\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC (Gallon):\u003c\/strong\u003e 808282184360\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSizes \u0026amp; Options\u003c\/h3\u003e\u003cp\u003eThis oil is sold in two sizes on one product line: Quart (946 ml) for smaller top-offs and Gallon for full oil changes or larger-capacity engines. Choose the Quart for topping off between changes or for engines with small oil capacities, and choose the Gallon for a complete oil change or to keep a larger reserve on hand. Both sizes are the same 10W-30 full synthetic formulation, so the choice comes down to the volume you need.\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat size options does Sierra 10W-30 Synthetic Marine Engine Oil come in?\u003c\/strong\u003e Sierra 10W-30 Full Synthetic Marine Engine Oil is available in two sizes: a 1 Quart (946 ml) bottle and a 1 Gallon container, both containing the same full synthetic formulation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this oil certified for marine engines?\u003c\/strong\u003e Yes, Sierra 10W-30 Full Synthetic Marine Engine Oil is NMMA FC-W Certified and rated API-SL, meeting the certification standard required for 4-stroke outboard and sterndrive engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich engines is this oil designed for?\u003c\/strong\u003e This 10W-30 full synthetic formula is formulated specifically for 4-stroke outboard and sterndrive engine technology and is recommended for use in both outboard and sterndrive applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I decide between the Quart and Gallon size?\u003c\/strong\u003e Choose the Quart (946 ml) of Sierra 10W-30 Synthetic Marine Oil for topping off oil levels or for engines with smaller oil capacities, and choose the Gallon size for a full oil change or to keep a larger supply on hand; both sizes are the identical formulation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this oil perform well in cold weather starts?\u003c\/strong\u003e Yes, the synthetic base oil in this Sierra 10W-30 blend offers faster lubrication at startup in low temperatures, helping protect engine components sooner on cold starts.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow does this oil handle high engine temperatures?\u003c\/strong\u003e Sierra 10W-30 Full Synthetic Marine Engine Oil provides excellent protection at high temperatures thanks to its balanced additive system and synthetic base oil.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this oil reduce oil consumption between changes?\u003c\/strong\u003e The balanced additive system in this 10W-30 synthetic oil gives greater resistance to oxidation, which results in lower oil consumption compared to a non-synthetic formulation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a full synthetic oil or a blend?\u003c\/strong\u003e Sierra 18-9690 is a full synthetic marine engine oil, using a special blend of synthetic base oil combined with a balanced additive system that exceeds FC-W requirements.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat container does the Quart size come in?\u003c\/strong\u003e The Quart size of Sierra 10W-30 Full Synthetic Marine Engine Oil (946 ml) is packaged in a bottle.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use this oil in a 2-stroke engine?\u003c\/strong\u003e No, Sierra 10W-30 Full Synthetic Marine Engine Oil is formulated for 4-stroke outboard and sterndrive engine technology, not 2-stroke applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the viscosity grade of this Sierra marine oil?\u003c\/strong\u003e This product is a 10W-30 viscosity grade full synthetic marine engine oil.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Quart","offer_id":48988062974171,"sku":"SIE-18-9690-2","price":17.32,"currency_code":"USD","in_stock":true},{"title":"Gallon","offer_id":48988063006939,"sku":"SIE-18-9690-3","price":63.46,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-9690-3.png?v=1784938603","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-9690-10w-30-fc-w-full-synthetic-marine-engine-oil-available-in-quart-and-gallon","provider":"Good Vibes Marina","version":"1.0","type":"link"}