Mercury – Water Separating Fuel Filter | Fuel System Component | Corrosion-Resistant Steel | 18458T3

Overview

Clean fuel keeps your outboard running strong, and the Mercury Marine 18458T3 Water Separating Fuel Filter is built to do exactly that. Designed for 1995 and earlier Mercury and Mariner V6 TwoStroke EFI/DFI outboards, this filter protects your engine from both debris and water contamination. It features a 10-micron filtration element and a black screw-in water sensor, giving you the same reliable performance Mercury builds into its factory systems. Simple to install and built for harsh marine conditions, this filter is an essential part of keeping your engine healthy and your fuel clean.

Key Features

• Purpose: Separates water and contaminants from fuel before it reaches the engine.
• Design: Screw-on 10-micron fuel filter with a black screw-in water sensor for early warning of water buildup.
• Material: Made with corrosion-resistant steel housing and epoxy-coated interior for added protection.
• Performance: Removes harmful particles and water to maintain efficient combustion and smooth operation.
• Ease of Use: Simple spin-on design for quick replacement during service or winterization.

Engine & Boat Compatibility

• Mercury and Mariner V6 EFI/DFI TwoStroke outboards (1995 and earlier).
• Commonly installed on bass boats, offshore rigs, and high-performance fishing setups.
• Works in both freshwater and saltwater environments.
• Designed to fit systems using the black water sensor plug connection.

Performance & Practical Benefits

The 18458T3 filter gives your outboard clean, dry fuel — exactly what it needs for smooth starts, efficient combustion, and full power under load. The 10-micron element catches tiny particles while the water sensor monitors for moisture buildup that can lead to corrosion or misfiring.

Each filter is built to Mercury’s exacting standards, with a steel shell tough enough to withstand vibration, heat, and salt exposure. Once installed, it provides season-long protection and peace of mind. Replace it annually or every 100 hours, and your engine will thank you with longer life and consistent performance.

Why Buy OEM

Fuel filters are the first line of defense for your engine’s health — and one place you shouldn’t compromise. The Mercury 18458T3 is a genuine OEM filter, designed for Mercury’s EFI and DFI systems to deliver precise flow and filtration. Aftermarket filters often use cheaper media or weaker casings that can collapse or leak under pressure.

With Mercury’s OEM filter, you get proper fitment, tested filtration, and long-term corrosion resistance. It’s the kind of part that doesn’t just meet the standard — it defines it. Install it once, trust it every trip.

FAQ

Q1: Which engines does this filter fit?
It fits Mercury and Mariner V6 EFI/DFI TwoStroke outboards (1995 and earlier) with black water sensor connections.

Q2: What’s included in the filter assembly?
The kit includes the spin-on fuel filter and a black screw-in water sensor.

Q3: How often should it be replaced?
Replace it every 100 hours of operation or once per season for best performance.

Q4: What’s the difference between this and the 18458T4 filter?
The 18458T3 includes a black sensor for older (pre-1996) engines; later models use a blue sensor connection.

Q5: Is it suitable for saltwater boats?
Yes — the housing is coated and corrosion resistant, designed for long-term marine exposure.