Mercury – High Performance Oil Filter | MerCruiser Sterndrive & Inboard Series | Synthetic High-Efficiency Media | 858004Q

Overview
A dependable oil filter doesn’t just keep your engine running—it lets you enjoy your time on the water without thinking twice about what’s happening under the hatch. When you’re cruising a long stretch of open lake or easing into a busy marina, you want to feel that smooth, steady hum that only comes from an engine protected the right way. The Mercury Marine part number 858004Q High Performance Oil Filter delivers that peace of mind. It’s designed for boaters who expect reliability, clean oil flow, and long-term protection every time they turn the key.

Key Features

• High-efficiency synthetic filtration media removes up to 97% of oil contaminants

• Anti-drain back valve ensures lubrication at startup and helps prevent dry starts

• Thick, reinforced metal shell offers superior strength and corrosion resistance

• Designed for MerCruiser sterndrive and inboard engines built by General Motors and Mercury Marine

• Built to Mercury Marine OEM specifications for precise flow and filtration

Engine & Boat Compatibility

• Fits MerCruiser sterndrive and inboard engines built by General Motors (excluding V6 engines with block-mounted filters)

• Fits Mercury Marine 4.5-liter and 6.2-liter engines

• Ideal for cruisers, bowriders, sport boats, deck boats, and family runabouts

• Suitable for boats that demand consistent oil protection under high load and long run times

Performance & Practical Benefits
A great oil filter has a quiet but powerful job. The 858004Q keeps your engine’s oil clean, smooth, and free of the fine contaminants that slowly chip away at performance. With its synthetic media, you’ll notice more consistent oil pressure and steadier temperature control, even when the engine is working hard through brisk acceleration or long, steady cruises.

The anti-drain back valve is a feature boaters appreciate more than they realize. It keeps oil where it needs to be, ensuring the engine is protected the instant it fires. No dry start. No harsh knock. Just a clean, smooth ignition that sets the tone for the whole day.

Once installed, the filter feels solid—tight, secure, and ready to handle vibration and constant water movement. The metal shell is significantly thicker than many aftermarket options, which means it can endure the pounding of rough water and the heat of long trips without weakening. Maintenance becomes simple, predictable, and satisfying. Spin it off, install the new one, and you’re right back to enjoying your boat without worry.

Why Buy OEM
Mercury OEM parts aren’t just convenient—they’re engineered around the exact needs of your engine. The 858004Q is built to deliver the right balance of oil flow, contaminant control, and startup protection. Aftermarket filters often fall short, either filtering too loosely or restricting flow. With OEM, you get long-term reliability, correct bypass calibration, and a perfect fit every single time. For boaters who take engine health seriously, sticking with Mercury OEM parts is the smartest, most practical choice.

FAQ

Q1: Which engines does the Mercury 858004Q High Performance Oil Filter fit?
It fits MerCruiser sterndrive and inboard engines built by General Motors (except block-mounted V6 filters) and Mercury Marine 4.5L and 6.2L engines.

Q2: What makes this filter different from aftermarket options?
Its synthetic media, reinforced shell, and anti-drain back valve are engineered to meet Mercury’s exact OEM standards—delivering superior filtration and startup protection.

Q3: How do I know if this is the correct replacement?
Check your service manual or current filter. If your engine specifies part number 858004Q, this is the correct choice.

Q4: Can it be used in both saltwater and freshwater?
Yes. Its corrosion-resistant shell and high-efficiency media perform reliably in both environments.

Q5: Is installation straightforward?
Definitely. If you’ve changed an oil filter before, this one threads on cleanly and tightens with a standard oil filter wrench.