Sierra Full Synthetic SAE 30 4-Cycle Marine Engine Oil – 1 Qt
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You have 30 days to request a return. All sale items are final sale.
Sierra Full Synthetic SAE 30 4-Cycle Marine Engine Oil – 1 Qt
Engineered specifically for the demands of marine engines, this full synthetic SAE 30 oil delivers superior protection across the full range of operating conditions — from cold morning startups to extended hours under load. The synthetic base oil and balanced additive system exceed FC-W (Four-Cycle Water-cooled) certification requirements, making it a step above conventional marine oils.
Compatible with both gasoline and diesel inboard and sterndrive engines, this oil is a reliable choice for boaters who want maximum protection without compromise.
Key Benefits
- Exceeds FC-W certification requirements for 4-cycle water-cooled marine engines
- Full synthetic formula provides superior protection during startup, operation, and storage
- Reduces friction and wear for extended engine life
- Helps reduce oil consumption and supports better fuel economy
- Compatible with gasoline and diesel inboard and sterndrive engines
Specifications
- Viscosity: SAE 30
- Type: Full Synthetic
- Volume: 1 Quart
- Engine Type: 4-Cycle (gasoline & diesel)
- Application: Inboard & Sterndrive (I/O)
- Certification: FC-W
Related Products
- Sierra Full Synthetic SAE 30 Marine Engine Oil – 5 Qt
- Sierra 25W-40 4-Stroke Marine Engine Oil – 1 Qt
- Sierra Synthetic Blend 25W-40 Marine Engine Oil – 1 Qt
- Sierra 10W-30 Mineral Marine Outboard Engine Oil – 1 Qt
Parts Desk Insights
SAE 30 full synthetic is the right call for inboard and sterndrive engines that specify a straight-weight oil — particularly older MerCruiser and Volvo Penta applications where the OEM calls for SAE 30. If your engine manual specifies a multi-viscosity like 25W-40, check our Sierra 25W-40 instead. The full synthetic formula is especially worthwhile if your boat sits for extended periods — it holds its protective film better than conventional oil during storage and resists moisture contamination. Best used for annual oil changes on freshwater or saltwater inboard/sterndrive engines.
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.