Quicksilver 4-Stroke Engine Oil – 4L | Part 8M0078634
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Quicksilver 4-Stroke Engine Oil – 4 Litre
| Part Number | 8M0078634 |
| OEM Reference | 92-8M0078634 |
| Brand | Quicksilver (Mercury Marine) |
| Official Product Type | 4-Stroke Marine Engine Oil |
| Volume | 4 Litres (approx. 1.06 US gallons) |
| System | Engine Lubrication – Crankcase |
| Packaged Weight | approx. 4.2 kg |
About This Oil
This is the OEM-specified 4-stroke crankcase oil for Mercury and MerCruiser gasoline-powered outboard and sterndrive engines. Formulated specifically for the sustained high-load, corrosive conditions of marine use, it protects against wear, corrosion, and deposit build-up — keeping your engine running clean between service intervals. Sold in a 4-litre container.
Compatible Applications
- Mercury 4-stroke outboard engines (all displacements requiring 4-stroke crankcase oil)
- MerCruiser sterndrive engines (gasoline 4-stroke)
- Mariner 4-stroke outboard engines
- Verify compatibility against your engine's serial number and current Mercury parts diagram before ordering
Service Interval
Change engine oil and filter at the interval specified in your Mercury or MerCruiser service manual — typically every 100 hours or annually, whichever comes first. Always replace the oil filter at each oil change.
Technical FAQ
Q: Can I use automotive 4-stroke oil instead?
A: Not recommended. Marine engines run under sustained high load in a corrosive saltwater environment. OEM-spec marine oil contains additives specifically engineered for these conditions that automotive oils lack.
Q: Is this oil compatible with my older Mercury engine?
A: This oil meets current Mercury 4-stroke specifications. Consult your service manual or the Mercury parts diagram for your specific engine serial range to confirm.
Q: What viscosity is this oil?
A: Refer to the product label or your engine's service manual. Mercury 4-stroke outboards commonly use 25W-40 or 10W-30 depending on model year and operating temperature range.
Related Parts
- Mercury MerCruiser Quicksilver Oil Filter 822626Q15
- Mercury MerCruiser Quicksilver High Performance Oil Filter 858004K
- Mercury MerCruiser Quicksilver Oil Filter 866340K01
- Mercury Quicksilver Oil Filter 877761K01 – 75-150 HP FourStroke Outboard
- Mercury Quicksilver Oil Filter 877769K01 – L6 Verado Outboard
- Mercury MerCruiser Oil Pan Drain Plug Gasket – 8M0077608
- Browse all MerCruiser Marine Engine Parts
Parts Desk Insights
Best use case: Routine oil changes on Mercury and MerCruiser 4-stroke engines. This is the correct OEM oil for scheduled maintenance — not a substitute or aftermarket alternative. Ideal for owners who want to maintain warranty compliance and use the fluid specified in the Mercury service manual.
Common mistakes: Customers sometimes order this when they actually need gear lube for the lower unit — these are completely different products. If you're servicing the lower unit or gearcase, you need a gear lube product, not engine oil. Also confirm you need the 4-litre size; other volumes may be available. Always pair an oil change with a new oil filter.
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.