Sierra 9420CAT7 4-Stroke Mineral Marine Outboard Engine Oil, 10W-30, 55-Gallon Drum
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Sierra 9420CAT7 4-Stroke Mineral Marine Engine Oil, 10W-30 – 55-Gallon Drum
Purpose-built for marine 4-stroke outboard engines, Sierra 9420CAT7 is a premium mineral-base 10W-30 engine oil formulated to meet or exceed the lubrication requirements of Mercury, Yamaha, Johnson-Evinrude, Suzuki, and Honda outboards. The 55-gallon drum format is designed for marinas, service shops, and commercial operators who need a reliable, high-volume supply of quality engine oil on hand.
Key Features
- Marine-specific formulation — engineered to the demands of 4-stroke outboard engines, not repurposed automotive oil
- Anti-wear additives — reduce friction and protect engine internals under sustained load
- Corrosion protection — guards against moisture and salt exposure in the marine environment
- Sludge control — keeps engine internals cleaner for better long-term efficiency
- Low-temperature viscosity — supports reliable cold-weather starting
- Broad OEM compatibility — meets API SJ, CF-2, and CH-4 service classifications
Specifications
- Viscosity: SAE 10W-30
- Base stock: Mineral
- API service: SJ, CF-2, CH-4
- Volume: 55 US gallons (208 L)
- Part number: 9420CAT7 | SKU: 47-9420CAT7
- Compatible engines: Mercury, Yamaha, Johnson-Evinrude, Suzuki, Honda 4-stroke outboards
Best Use Case
The 55-gallon drum is the right format for marina service departments, mobile marine mechanics, and commercial operators running regular oil change programs across a fleet of 4-stroke outboards. Buying in drum quantity significantly reduces cost-per-service compared to case or gallon packaging, and eliminates the logistics of frequent reordering during peak season.
For smaller-volume needs, this oil is also available by the gallon and by the quart — see the Sierra 9420CAT3 10W-30, 1-Gallon and the Sierra 9420CAT2 10W-30, 1-Quart. For a synthetic blend upgrade with extended drain interval performance, see the Sierra 9421CAT2 Synthetic Blend 10W-30.
Parts Desk Insights
Best use case is marina shops and commercial operators running high-volume oil change programs on 4-stroke outboard fleets. The drum format offers the strongest cost-per-litre value in the Sierra 10W-30 line and is the practical choice for any operation doing more than 20–30 oil changes per season. Recommend confirming OEM oil specification with the customer — while this oil meets API SJ/CF-2/CH-4, some manufacturers (particularly Yamaha and Mercury) recommend their own branded oils or FC-W certified formulations for warranty compliance. For customers who want FC-W certification, redirect to the Sierra 9421CAT2 Synthetic Blend 10W-30 (FC-W) instead.
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.