Sierra 96903 10W-30 FCW Synthetic 4-Stroke Marine Oil — 1 Gal
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Full-Synthetic 4-Stroke Marine Engine Oil in a Gallon Size
Sierra 96903 delivers the same full-synthetic 10W-30 formulation as the quart-size 96902 — now in a gallon for owners and technicians who go through more oil each season. Built on a synthetic base oil with a precision-balanced additive system, it exceeds NMMA FC-W® certification requirements and is recommended for both 4-stroke outboard and sterndrive engines.
The gallon format offers a lower per-quart cost while maintaining the same superior protection: faster cold-start lubrication, excellent high-temperature stability, and greater oxidation resistance that helps reduce oil consumption over time.
Key Benefits
- Exceeds NMMA FC-W® Certified standards — not just meets them
- Synthetic base oil for superior film strength and thermal stability
- Faster lubrication at cold start — critical protection during the first seconds of engine operation
- Excellent high-temperature protection for hard-working marine engines
- Greater oxidation resistance helps reduce oil consumption between changes
- Recommended for both outboard and sterndrive 4-stroke applications
Also Available
- Sierra 96902 10W-30 FCW Synthetic 4-Stroke Marine Oil — 1 Qt — quart size for single-engine or occasional use
- Sierra 94203 10W-30 FCW 4-Stroke Outboard Oil — 1 Gal — conventional formula gallon option
- Sierra 9394 Oil Change Kit — complete service kit with filter, gasket, funnel, maintenance sticker, and shop towel
Parts Desk Insights
The gallon synthetic is the best recommendation for performance-focused customers who do multiple oil changes per season and don’t want to compromise on protection. Best use case: high-hour engines, twin-engine boats, year-round operators, and anyone whose manufacturer approves or recommends a full-synthetic FC-W oil. The gallon format makes the synthetic upgrade more cost-effective per quart — an easy conversation when a customer is already reaching for the conventional 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.