Sierra 9440CAT4 Synthetic Blend 25W-40 FC-W Marine Engine Oil – 5 Qt
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Sierra 9440CAT4 Synthetic Blend 25W-40 FC-W Marine Engine Oil – 5 Qt
Engineered specifically for modern 4-stroke inboard and sterndrive marine engines, this synthetic blend oil delivers reliable protection whether your engine runs a catalyst-equipped exhaust system or not. The 25W-40 viscosity grade maintains a stable oil film across a wide temperature range — from cold morning starts to sustained high-RPM operation on open water.
Sold in 5-quart containers. Case quantities available.
Key Benefits
- NMMA FC-W® Certified and API-SL rated — meets OEM requirements for most inboard and sterndrive engines
- Catalyst-compatible formula protects emission systems from phosphorus depletion using advanced ZDDP anti-wear technology
- Enhanced detergents and dispersants keep internals clean and prevent sludge buildup
- Corrosion inhibitors protect against moisture-related damage common in marine environments
- Resists viscosity breakdown under high-load, high-temperature conditions
- Industry-leading wear protection for extended engine life
Specifications
- Part Number: 9440CAT4 (SKU: 47-9440CAT4)
- Viscosity: 25W-40
- Certification: NMMA FC-W®, API-SL
- Volume: 5 Quarts
- Application: 4-stroke inboard and sterndrive engines
Parts Desk Insights
Best use case: This is the go-to oil for inboard and sterndrive engines (MerCruiser, Volvo Penta, Indmar, PCM, etc.) that specify a 25W-40 FC-W rated oil — especially engines with catalytic exhaust systems where phosphorus-safe formulas are required. If you only need a single quart for a top-up, see the Sierra 9440CAT2 Synthetic Blend 25W-40 FC-W Marine Engine Oil – 1 Qt. For high-volume or commercial use, the Sierra 9440CAT7 Synthetic Blend 25W-40 FC-W Marine Engine Oil – 55-Gallon Drum offers the best value per litre. For outboard engines requiring 10W-30, see the Sierra 9421CAT3 Synthetic Blend 10W-30 FC-W 4-Stroke Outboard Engine Oil – 1 Gallon.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.