AMSOIL for marine and outboards
Marine engines operate in a high-load environment where the correct engine oil, lower-unit lubricant and fuel-system products matter. Use the dedicated AMSOIL Marine Outboard lookup to match your engine.
Marine Engine Oil
Engine oils intended for marine applications and common marine viscosities.
Gear Oil
Lubricants for gear-driven marine components where applicable.
Fuel Additives
Fuel-system products for gasoline and diesel applications.
Match the exact engine
Outboards can have different lubrication requirements based on manufacturer, model, horsepower and year. Enter the exact engine information rather than choosing only by horsepower or brand.
Marine engines operate in a demanding environment
Boat engines combine sustained load, moisture, seasonal storage and corrosion concerns. Choosing the correct oil is not just about viscosity; the engine type, manufacturer specification, two-stroke or four-stroke design and operating conditions all matter.
Four-stroke engines
Four-stroke outboards and inboards require engine oil that matches the manufacturer’s viscosity and marine performance requirements.
Two-stroke engines
Two-stroke applications may use oil injection or premix and can have very specific lubricant requirements. Match the product to the engine design and required specification.
Lower units & gearcases
Marine gearcases operate under heavy load and may be exposed to water intrusion. Correct gear lubricant and regular inspection are important parts of seasonal service.
Before and after the boating season
Check engine oil, gear lube, filters, fuel treatment and corrosion protection as part of your seasonal routine. If gear lube appears milky or shows evidence of water, investigate the source rather than simply refilling the unit.
Marine FAQ
Does every boat use the same marine oil?
No. Outboards, sterndrives, inboards and personal watercraft can require different products. Always identify the engine and required specification.
Is storage part of lubricant planning?
Yes. Fuel stability, corrosion protection and moisture control become especially important when a boat sits for an extended period.