Mercury – High Performance Oil Filter | MerCruiser Sterndrive & Inboard Series | Synthetic Filtration Media | 858004K

Overview

There’s a certain comfort in knowing your engine is protected long before you push the throttle forward. Clean oil isn’t just maintenance—it’s the lifeblood that keeps long summer cruises, early-morning runs, and family weekends running smooth. That’s why so many boaters stay loyal to Mercury’s High Performance Oil Filter 858004K. It’s built for those of us who want the confidence of an engine that’s ready for anything, whether you’re idling out of the marina or carving across open water with a warm breeze at your back.

Key Features

• Screw-on oil filter engineered for MerCruiser sterndrive and inboard engines
• High-efficiency synthetic filtration media removes over 97% of oil contaminants
• Designed for extended engine protection during high-load and long-run operation
• Reinforced housing for durability under vibration and sustained pressure
• Easy replacement with basic tools and an oil filter wrench

Engine & Boat Compatibility

• Fits all MerCruiser 4.5-liter and 6.2-liter sterndrive and inboard engines
• Compatible with GM-based marine engines except V6 models with block-mounted filters
• Ideal for bowriders, cruisers, runabouts, deck boats, and performance sport boats
• Suitable for both recreational and higher-demand boating applications

Performance & Practical Benefits

A great oil filter doesn’t draw attention—it simply lets your engine breathe cleaner, run cooler, and stay protected from the small contaminants that create big problems over time. With the 858004K installed, you’ll notice smoother operation and more consistent oil pressure across the entire RPM range. The synthetic filtration media captures the fine debris that circulates during hard acceleration, long no-wake zones, and extended family outings.

On the water, that translates into a steadier, quieter engine that feels secure even under heavy loads. The filter’s reinforced canister stands up to vibration and pressure fluctuations, giving you a strong sense of confidence when the water turns choppy or you open up the throttle. Fitment is tight and clean, threading on smoothly without fuss or guesswork. And because it’s designed specifically for MerCruiser engines, you won’t deal with leaks, mismatched seals, or a filter that runs hot.

Maintenance is simple—spin it off, spin the new one on, and know you’ve given your engine a fresh layer of protection. It’s the type of part that rewards consistency with long engine life, better performance, and fewer surprises down the line.

Why Buy OEM

When it comes to oil filtration, shortcuts just aren’t worth it. A genuine Mercury Marine part ensures you’re using a filter engineered around the exact flow rates, pressure demands, and contaminant sizes your MerCruiser engine encounters. Aftermarket filters often miss the mark on filtration density or bypass valve calibration, which can lead to premature wear or pressure drop. With OEM, you’re getting long-term reliability, a perfect fit, and the peace of mind that comes from using the same filter Mercury installs from the factory. It’s practical, proven, and the safest investment you can make for your engine’s health.

FAQ

Q1: Which engines does the Mercury 858004K High Performance Oil Filter fit?

It fits MerCruiser 4.5-liter and 6.2-liter sterndrive and inboard engines, along with select GM-based marine engines except V6 models with block-mounted filters.

Q2: What makes this filter better than aftermarket alternatives?

Its synthetic media removes more contaminants, maintains oil pressure more consistently, and matches Mercury’s exact OEM specifications.

Q3: How do I know if this is the correct replacement?

Check your existing filter or owner’s manual for part number 858004K. If it’s listed, this is the correct fit.

Q4: Can it be used in both saltwater and freshwater?

Yes, it performs reliably in both environments and protects against the demanding conditions of marine use.

Q5: Is installation straightforward for most boat owners?

Absolutely. With a standard filter wrench and basic tools, replacement is quick and simple.