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Sierra Marine 4 Stroke Marine Engine Oil

(45 products)

Performing regular oil changes for your outboard engine with Sierra Marine 4-Stroke Marine Engine Oil is crucial for lubrication and optimal performance on the water. PartsVu offers a complete catalog of Sierra Marine Marine Engine Oil for all engine makes, models, and weights including 10W-30 and 25W-40.

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  • Sierra - SYNTHETIC BLEND 4-CYCLE CATALYST INBOARD/STERNDRIVE ENGINE OIL 25W-40 - Quart - 9440CAT2

    SIERRA

    Sierra - SYNTHETIC BLEND 4-CYCLE CATALYST INBOARD/STERNDRIVE ENGINE OIL 25W-40 - Quart - 9440CAT2

    $12.49 $13.39
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  • Sierra - 25W-40 FC-W Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - 5 Quart - 4 Pack - 1894404

    SIERRA

    Sierra - 25W-40 FC-W Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - 5 Quart - 4 Pack - 1894404

    $230.92
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  • Sierra - 25W-40 Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - Quart - 6 Pack - 1894402

    SIERRA

    Sierra - 25W-40 Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - Quart - 6 Pack - 1894402

    $76.80
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  • Sierra - 25W-40 Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - Quart - 12 Pack - 1894402

    SIERRA

    Sierra - 25W-40 Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - Quart - 12 Pack - 1894402

    $153.60
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  • Sierra - 25W-40 Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - Quart - 2 Pack - 1894402

    SIERRA

    Sierra - 25W-40 Synthetic Blend 4 Stroke Inboard/Sterndrive Engine Oil - Quart - 2 Pack - 1894402

    $25.60
    Learn More
  • Sierra - 10W-30 Synthetic 4 Stroke Engine Oil - Quart - 12 Pack - 96902

    SIERRA

    Sierra - 10W-30 Synthetic 4 Stroke Engine Oil - Quart - 12 Pack - 96902

    $223.20
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  • Sierra - SAE 25W-40 FC-W 4 Stroke Marine Engine Oil - Quart - 12 Pack - 94002

    SIERRA

    Sierra - SAE 25W-40 FC-W 4 Stroke Marine Engine Oil - Quart - 12 Pack - 94002

    $140.76
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  • Sierra - 25W-40 FC-W 4 Stroke Stern Drive Engine Oil - 5 Quart - 2 Pack - 9400CAT4

    SIERRA

    Sierra - 25W-40 FC-W 4 Stroke Stern Drive Engine Oil - 5 Quart - 2 Pack - 9400CAT4

    $118.00
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  • Sierra - SAE 25W-40 FC-W 4 Stroke Marine Engine Oil - Quart - 94002

    SIERRA

    Sierra - SAE 25W-40 FC-W 4 Stroke Marine Engine Oil - Quart - 94002

    $11.73 $13.39
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Sierra Marine 4 Stroke Outboard Engine Oil - Resources & Information

Sierra Marine 4 Stroke Marine Engine Oil is specifically formulated to lubricate the engine, reduce friction, and prevent wear and tear on the internal components of the engine. Sierra Marine Oil also helps to keep the engine running smoothly, improve fuel efficiency, and extend the life of the engine.

PartsVu offers a complete selection of Sierra Marine 4-Stroke Marine Engine Oil for all weights and grades. Whatever type and quantity of Sierra Oil you need to maintain your outboard motor, PartsVu has what you need to get the job done. 

Need help servicing your boat and outboard engine? PartsVu regularly publishes helpful how-to guides and other valuable maintenance information to help boaters service their outboard engines, boats, trailers, and more. Browse the PartsVu Xchange, our outboard maintenance blog, for a wide range of relevant topics and review the FAQ section below, covering everything you need to know about maintaining your boat in confidence.

Sierra Marine 4 Stroke Marine Engine Oil FAQ

Where can I learn more about using Sierra Marine 4-Stroke Engine Oil on my boat and outboard motor?

PartsVu has plenty of resources for everything you need to know about marine engine oil for your boat and all models of popular outboard motors. Start with the following guides and be sure to use the search bar to find plenty of other useful guides to maintain your boat in confidence:

What's the difference between 25w-40 and 25w-50?

The difference between 25W-40 and 25W-50 oil is the viscosity, or thickness, of the oil at higher temperatures. The first number, 25, refers to the oil's viscosity, or flow, at low temperatures (in this case, at -25°C). The W stands for "winter," and indicates that the oil has been certified to meet certain viscosity requirements at low temperatures. The second number, 40 or 50, refers to the oil's viscosity at higher temperatures (in this case, at 100°C). The higher the second number, the thicker the oil will be at higher temperatures.

In general, 25W-40 oil will have a lower viscosity at higher temperatures than 25W-50 oil. This means that 25W-40 oil will flow more easily at high temperatures and may provide better protection for engines that operate at high speeds or under heavy load. 25W-50 oil, on the other hand, may provide better protection for engines that operate in very hot conditions, such as in a boat in the tropics.

It's important to use the oil that is recommended by the manufacturer of your engine. Different engines have different lubrication requirements, and using the wrong oil can potentially cause damage or decreased performance.

What's the difference between 25w-40 and 10w-30?

The difference between 25W-40 and 10W-30 oil is the viscosity, or thickness, of the oil at different temperatures. The first number, 10 or 25, refers to the oil's viscosity, or flow, at low temperatures (in this case, at -25°C). The W stands for "winter," and indicates that the oil has been certified to meet certain viscosity requirements at low temperatures. The second number, 30 or 40, refers to the oil's viscosity at higher temperatures (in this case, at 100°C). The higher the second number, the thicker the oil will be at higher temperatures.

In general, 10W-30 oil will have a lower viscosity at both low and high temperatures than 25W-40 oil. This means that 10W-30 oil will flow more easily at both low and high temperatures and may provide better protection for engines that operate at high speeds or under heavy load. 25W-40 oil, on the other hand, may provide better protection for engines that operate in very hot conditions, such as in a boat in the tropics.

What's the difference between marine oil and car oil?

Marine oil and car oil are similar in many ways, but there are also some important differences. Both types of oil are designed to lubricate the moving parts of an engine, reduce wear, and help keep the engine running smoothly. Both types of oil are also rated using the same numbering system (e.g., 10W-30, 15W-40, etc.), which indicates their viscosity (thickness) at different temperatures.

However, there are a few key differences between marine oil and car oil:

  1. Additives: Marine oil typically has additional additives to protect against the unique challenges that marine engines face, such as saltwater corrosion and extreme temperature fluctuations.
  2. Viscosity: Marine oil is often formulated to maintain a consistent viscosity at a wider range of temperatures than car oil. This is because marine engines are often subjected to more extreme temperature fluctuations than car engines.
  3. Compatibility: It is generally not recommended to use car oil in a marine engine, or vice versa. Marine engines often have different lubrication requirements than car engines, and using the wrong oil can potentially cause damage or decreased performance.

It is generally best to use the oil recommended by the manufacturer of your engine, as each manufacturer has specific oil formulation requirements for their engines.

What absorbs motor oil?

There are several materials that can be used to absorb motor oil, including:

  1. Oil absorbent pads, absorbent mats for oil, and rolls: Oil absorbant pads are made from materials like polypropylene or cellulose, which are highly absorbent and can quickly soak up oil spills.
  2. Clay-based absorbents: These are made from bentonite clay, which is highly absorbent and can effectively soak up oil spills.
  3. Oil-only absorbents: These are made from materials that are specifically designed to absorb oil and other petroleum-based substances, but not water. They are often used in marine environments to prevent oil spills from contaminating the water.
  4. Boom barriers: These are floating barriers that are used to contain and absorb oil spills in bodies of water. They are made from materials like polypropylene or polyurethane, which are highly absorbent and can effectively soak up oil.
  5. Sorbent socks: These are long, tube-shaped absorbents that can be placed around oil spills to contain and absorb them. They are made from materials like polypropylene or cellulose, which are highly absorbent and can quickly soak up oil.

It's important to use the right type of absorbent material for the specific type of spill you are dealing with. For example, oil only absorbent pads may not be effective for certain types of spills that other sorbents are designed for.

How do I perform an oil change on my 4-stroke outboard engine? 

Spent engine oil can be removed from the engine by extraction or via the oil pan drain screw plug. The extraction method requires the use of a vacuum extractor which is inserted down the dipstick tube and uses suction to pull the spent oil from the pan. Oil extraction tends to be very clean and is probably the most widely used among marine technicians. Alternatively, the drain screw itself can be removed. Be sure to have plenty of drain pan capacity as some engines can hold up to seven quarts of oil. We also recommend an oil absorbent pad like the 3M HP156 pad to catch any errant drips that might soil your driveway or lawn.

In cold climates, it may be helpful to start and warm the engine before draining the oil to thin it slightly. However, if possible, perform the engine oil change as the first part of the service since the maximum amount of oil will be in the oil pan already from the engine sitting allowing you to extract as much old oil as possible to minimize contamination of your fresh oil.

As the old oil is draining, you can work on removing the engine oil filter. Depending on your specific model, your filter may have a drain lip that helps to keep the mess to a minimum when you unscrew the old filter. However, most older engines do not have this feature. We suggest being prepared with plenty of absorbent rags or placing a small cup that is cut to size below the filter before removal. Using a PartsVu Maintenance Essentials filter wrench is the best way to loosen the filter. Remember when you reinstall the filter, over-tightening will only make your life more difficult when you are ready for the next service. Some technicians puncture the old filter allowing trapped oil to drain back into the block before removal, but this will ruin your ability to take the filter apart for further inspection.

Several laboratories provide performance testing of used oils, allowing you to learn more about the health of your engine. Blackstone Labs is one such provider, and they have a convenient mail-in kit that includes everything you need to submit an oil sample. They can also test gear oils, hydraulic fluids, and oils from your other vehicles or toys. Oil test results can tip you off to an accelerated wear condition inside of your engine long before any other symptoms show up. If you still want to know more about your engine, purchase an oil filter cutter and open the spent filter to look for evidence of contamination and metal dust or shavings.

Once you have inspected your spent oil and filter, set them aside for proper disposal. If you removed the drain screw to empty your oil, carefully reinstall the drain plug. The new oil filter should be removed from its package and the o-ring lubricated with a thin coat of fresh engine oil. Spin on the new oil filter and gently tighten to seat the o-ring without over-torquing.

If you are uncertain as to which oil is best for your application, consult your owners’ manual. Loosen the yellow oil fill plug on the top of the engine and pour in fresh oil. We recommend adding slightly less than the stated capacity. With the engine trimmed down, check the oil level on the dipstick after allowing a few minutes for the oil to drain into the oil pan properly. Filling the oil to the lower level on the dipstick will help you to measure if the oil level changes over time with the engine in operation.