Mercury Fogging Oil 858081K03 – 12 oz Storage Protection Spray
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Mercury 858081K03 Fogging Oil – 12 oz Spray
Part Number: 858081K03 (also listed as 92-858081K03)
Brand: Mercury Marine
Official Product Type: Storage Seal / Fogging Oil
Size: 12 oz aerosol spray can
System: Engine Lubrication & Corrosion Protection
Condition: New OEM
What It Does
Mercury 858081K03 is a genuine OEM fogging oil designed to protect internal engine surfaces during winterization and long-term storage. Its heavy, sticky formula coats cylinder walls, pistons, and other metal surfaces to prevent rust and corrosion when the engine sits idle — reducing the risk of cylinder or piston damage at restart.
Compatible Applications
- Mercury and MerCruiser 2-stroke gasoline outboards
- Mercury and MerCruiser 4-stroke gasoline outboards
- MerCruiser sterndrive engines (carbureted, fuel-injected, and catalyzed)
- Other gasoline-powered marine equipment
This is a maintenance chemical, not a model-specific hard part. Serial number confirmation is not required. Always follow the storage procedure in your engine's owner's manual.
Service Interval
Use once per storage season — typically at the start of winterization or before any extended lay-up period of 30 days or more.
Supersedes / Related Part Numbers
- 858081K03 — current Mercury OEM part number
- 92-858081K03 — alternate prefix format, same part
- Quicksilver-branded equivalent: Quicksilver Rust Guard 858081KC3
Kit Contents
Single 12 oz aerosol spray can. No additional components included.
Related Products
- Quicksilver Rust Guard Rust Inhibitor 12 oz – 858081KC3
- Mercury Antifreeze –50°F, 1 Gallon – 8M0073201
Parts Desk Insights
Best Use Case: This is a seasonal must-have for any Mercury or MerCruiser owner laying up their engine for winter or an extended period. It's especially important for engines stored in humid environments where internal corrosion can develop quickly on unprotected metal surfaces.
Common Mistakes: Customers sometimes skip fogging oil thinking their engine oil provides enough protection during storage — it doesn't. Engine oil drains away from cylinder walls when the engine sits, leaving bare metal exposed. Another common error is applying fogging oil without also running antifreeze through the cooling system; both steps are needed for complete winterization. Always follow the procedure in your owner's manual for the correct application method (typically sprayed into the air intake while the engine is running, then shut down immediately after).
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 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.