Sierra 94104 Full Synthetic SAE 30 4-Cycle Marine Engine Oil, 5 Quarts
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Sierra 94104 Full Synthetic SAE 30 4-Cycle Marine Engine Oil – 5 Quarts
Purpose-built for gasoline and diesel inboard and sterndrive engines, Sierra 94104 is a full synthetic SAE 30 marine engine oil formulated with a special blend of synthetic base stocks and a balanced additive system that exceeds FC-W marine engine oil requirements. It delivers superior protection across the full engine lifecycle — from cold starts and hard running to long-term storage.
The 5-quart jug is the right size for a complete oil change on most inboard and sterndrive engines, covering the typical 4–5 quart sump capacity in a single container.
Key Features
- Full synthetic formulation — exceeds FC-W marine engine oil requirements; superior protection versus conventional and synthetic-blend oils
- Startup & storage protection — maintains a protective oil film on engine surfaces during cold starts and extended lay-up periods
- Friction & wear reduction — reduces metal-to-metal contact for extended engine life and lower operating temperatures
- Reduced oil consumption — full synthetic base resists burn-off and volatility better than conventional oils
- Improved fuel economy — lower internal friction translates to measurable efficiency gains over time
- Gasoline & diesel compatible — suitable for both fuel types in inboard and sterndrive applications
Specifications
- Viscosity: SAE 30
- Base stock: Full synthetic
- Certification: FC-W (exceeds requirements)
- Application: Gasoline and diesel inboard and sterndrive engines
- Volume: 5 US quarts (4.73 L)
- Part number: 94104 | SKU: 47-94104
Best Use Case
The 94104 is the ideal choice for inboard and sterndrive owners who want full synthetic protection for a complete seasonal oil change. The 5-quart size covers most inboard engine sump capacities in a single purchase, making it a convenient one-stop solution for DIY engine maintenance. It’s particularly well-suited for engines that sit for extended periods between uses, where the superior film retention of full synthetic oil provides meaningful protection during storage and on first start-up of the season.
Also available in a 1-Quart size (94102) for top-ups or smaller engine sumps. For outboard engine applications, see the Sierra 9421CAT2 Synthetic Blend 10W-30 FC-W (1 Qt.) or the Sierra 9421CAT3 Synthetic Blend 10W-30 FC-W (1 Gallon).
Parts Desk Insights
Best use case is the inboard or sterndrive owner doing a full seasonal oil change — the 5-quart jug is sized to cover most common inboard sump capacities (4–5 qt) in a single container, which is a genuine convenience selling point. Lead with the FC-W certification and full synthetic protection when positioning against conventional or synthetic-blend alternatives. Key distinction: this oil is for inboard and sterndrive engines only — not for outboard motors. Redirect outboard customers to the 9420 or 9421 series. The startup and storage protection benefit is a strong talking point for seasonal boaters who winterize and want peace of mind on spring commissioning. Pair with the appropriate oil filter for the customer’s engine as an add-on sell.
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.