Every boater knows the feeling of turning the key and hearing that smooth, confident hum from a well-protected engine. It’s the sound of clean oil moving through clean pathways — exactly what this Mercury Marine oil filter is built to support. Part number 866340K01 isn’t flashy, and that’s the point. It’s a dependable piece of hardware designed to keep one of your engine’s most important systems healthy and free from harmful contaminants. When you’re out on the water with family or friends, that kind of silent reliability goes a long way.
Key Features
High-efficiency filtration for cleaner engine oil
M-Pleated filter media traps a wide range of contaminants
Corrosion-resistant coated metal shell
Designed for secure, leak-free sealing
Works with common marine oil filter wrenches
Engine & Boat Compatibility
Fits 4.5L and 6.2L MerCruiser sterndrive and inboard engines
Also compatible with GM engines except V6 models with block-mounted filters
Works on runabouts, cruisers, tow-boats, and sport boats
Suitable for both freshwater and saltwater use
Performance & Practical Benefits
Oil filters often go unnoticed until something goes wrong — but with this Mercury filter, you’re giving your engine the kind of clean, consistent lubrication it needs to perform its best. The advanced M-Pleated media captures debris, moisture, and microscopic contaminants that could otherwise shorten engine life. The result is smoother running, cleaner idle, and long-term protection against internal wear.
The corrosion-resistant shell is built for harsh marine environments. Even after seasons of heat cycling and moisture exposure, it still threads cleanly and seals tight. Because it’s engineered for Mercury’s filtration system, the flow rate and pressure characteristics match factory specifications exactly, giving your engine what it needs without starving or over-restricting oil movement.
Why Buy OEM
Oil filters are not all created equal — and in a marine environment, the difference matters. Mercury’s OEM filters handle higher moisture levels, wider temperature swings, and sustained engine loads better than generic replacements. If you want your oil to stay clean and your engine to stay healthy, an OEM filter is the right choice. It’s affordable insurance for your most valuable equipment.
FAQ
Q1: Which engines does this filter fit?
It fits MerCruiser 4.5L and 6.2L engines, plus select GM engines.
Q2: What makes this filter better than aftermarket?
Superior filtration media, better flow control, and corrosion-resistant materials.
Q3: How do I confirm it’s correct for my engine?
Match your engine model and confirm you do not have a block-mounted V6 filter.
Q4: Good for saltwater?
Yes — the shell and sealing materials are built for marine exposure.
Q5: Easy to replace?
Yes, with a standard oil filter wrench and proper access.
WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.
