Mercury – Water Separating Fuel Filter | Fuel System Component | Corrosion-Resistant Steel | 18458T4

Overview

A clean, water-free fuel supply is the key to reliable performance on the water. The Mercury Marine 18458T4 Water Separating Fuel Filter is built to keep your engine protected and running smooth. Designed for 1996 and newer Mercury and Mariner V6 EFI/DFI TwoStroke outboards, it captures harmful debris and separates water before it ever reaches your engine. Featuring a durable steel canister and a blue water sensor, it delivers the same factory-level protection Mercury engineers designed into their performance fuel systems.

Key Features

• Purpose: Removes water, dirt, and contaminants from your fuel before it enters the engine.
• Design: Spin-on 10-micron water-separating fuel filter with a blue screw-in water sensor.
• Material: Constructed with a corrosion-resistant steel housing and internal epoxy coating for long-term durability.
• Performance: Prevents power loss, stalling, and corrosion caused by contaminated fuel.
• Ease of Use: Quick, simple replacement with standard tools — perfect for annual service.

Engine & Boat Compatibility

• Mercury and Mariner V6 EFI/DFI TwoStroke outboards manufactured 1996 and later.
• Common on bass boats, offshore fishing rigs, center consoles, and sport cruisers.
• Works in both saltwater and freshwater environments.
• Built for systems using the blue water sensor connector.

Performance & Practical Benefits

The 18458T4 fuel filter does the critical job of keeping your fuel system clean and dry. The 10-micron filtration element traps microscopic particles while separating water that can rob power or corrode injectors. The integrated blue water sensor detects moisture early, helping you avoid potential damage before it starts.

Once installed, you’ll notice smoother acceleration, more consistent power, and fewer fuel-related issues. With its heavy-duty coating and marine-grade construction, it’s designed to last through long seasons on the water — whether you’re trolling all day or running wide open.

Why Buy OEM

Not all filters are created equal. Generic or automotive filters might look similar but can’t match Mercury’s marine-grade engineering. The 18458T4 is a genuine Mercury Marine part, built specifically for the pressures, flow rates, and corrosion challenges of EFI and DFI outboards.

Mercury tests every component under real-world marine conditions — salt, vibration, and ethanol-blended fuels — to ensure flawless performance. With OEM parts, you get the right fit, filtration accuracy, and long-term protection your engine deserves.

FAQ

Q1: Which engines does this filter fit?
It fits 1996 and newer Mercury and Mariner V6 EFI/DFI TwoStroke outboards using the blue sensor connector.

Q2: What’s included with the filter?
It includes the 10-micron water-separating fuel filter and the blue screw-in water sensor.

Q3: How often should I replace it?
Replace it annually or every 100 hours of use to maintain clean fuel flow.

Q4: What’s the difference between this and the 18458T3 model?
The 18458T4 uses a blue water sensor for newer (post-1996) engines, while the 18458T3 uses a black sensor for older models.

Q5: Is it suitable for saltwater operation?
Yes — it’s coated inside and out to resist corrosion and withstand marine conditions.