Best Fuel & Water Separators of 2025

Robert Reyes Avatar
Robert Reyes
Last Updated: Jan 5, 2025

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Fuel & Water Separators are essential components for any boat or marine vessel that runs on diesel fuel. These products are designed to remove water and other contaminants from the fuel before it reaches the engine, ensuring optimal performance and preventing damage. Fuel & Water Separators come in a variety of sizes and styles to fit different types of boats and engines. They feature high-quality filtration systems that effectively remove water, dirt, and other impurities from the fuel, providing reliable and efficient operation for the vessel. These products are a must-have for any boat owner who wants to protect their investment and ensure a smooth and safe boating experience.

At a Glance: Our Top Picks

CARMOCAR Fuel Filter Water Separator for Marine Outboard Motor Mercury Cover #TOP 1
CARMOCAR Fuel Filter Water Separator for Marine Outboard Motor Mercury
ftb score rating icon 9.8
Sierra International Marine Fuel Water Separator Kit Cover #TOP 2
Sierra International Marine Fuel Water Separator Kit
ftb score rating icon 9.7
CARMOCAR R12T Marine Fuel Separator Cover #TOP 3
CARMOCAR R12T Marine Fuel Separator
ftb score rating icon 9.5

Top 10 Fuel & Water Separators

#TOP 1

CARMOCAR Fuel Filter Water Separator for Marine Outboard Motor Mercury

WS-Z136
S3213 Assembly
CARMOCAR Fuel Filter Water Separator for Marine Outboard Motor Mercury Cover
CARMOCAR Fuel Filter Water Separator replacement for Marine Outboard Motor Mercury with 3/8" Barb x 1/4" NPT brass Fittings Replaces# S3213, S3214, 35-60494-1, S3213, 18-7932-1, 18-17928, 35-809097

The CARMOCAR Fuel Filter Water Separator is a high-quality replacement part for Marine Outboard Motor Mercury. Made of premium aluminum material, it offers long-lasting durability and reliability. The 3/8 NPT ports provide lower pressure drop rates, while the 10-micron filters are over 92% efficient at removing particles as small as 10 microns. The filter is a perfect fit for a variety of universal fuel applications and can trap the smallest particles and emulsified water from gasoline, reducing damage to your engine and other fuel delivery components.

What We Like
Constructed of premium aluminum material for long-lasting durability and reliability
10-micron filters are over 92% efficient at removing particles as small as 10 microns
3/8 NPT ports provide lower pressure drop rates
#TOP 2

Sierra International Marine Fuel Water Separator Kit

Sierra
18-7982-1
white
Sierra International Marine Fuel Water Separator Kit Cover
Sierra International 18-7982-1 Marine Fuel Water Separator Kit, white

Keep your boat's motor running smoothly with the Sierra International 18-7982-1 Marine Fuel Water Separator Kit. Its 90 GPH flow rate can satisfy even the most demanding engines. This kit is designed to prevent damage to sensitive fuel injection systems and remove over 99.8% of emulsified water from your gasoline, ensuring clean fuel reaches your engine. With over 90% efficiency in removing particles as small as 10 microns, the Sierra 10 micron filters provide superior filtration. The aluminum material and universal fit make it a durable and versatile option for any boat owner.

What We Like
High flow rate of 90 GPH to feed even the most demanding motors
Prevents damage to sensitive fuel injection systems
Removes over 99.8% of emulsified water and over 90% of particles as small as 10 microns for clean fuel
Aluminum material ensures durability and universal fit allows for versatility
#TOP 3

CARMOCAR R12T Marine Fuel Separator

r12t fuel filter
R12T Assembly
CARMOCAR R12T Marine Fuel Separator Cover
CARMOCAR Marine Fuel Water Separator/Diesel Fuel Filter/Water Separator for R12T MARINE SPIN-ON HOUSING 120AT NPT ZG1/4-19 Includes 2 fittings,2 plugs

The CARMOCAR R12T Separator is designed for easy installation and maintenance. Its spin-on design allows you to quickly replace the filter, saving you time and effort. The clear nylon bowl lets you monitor fuel quality visually, ensuring you always use clean fuel. With a self-venting drain, you can easily remove unwanted water and debris without disassembling the unit. This feature not only simplifies maintenance but also optimizes engine performance by ensuring water-free fuel flows through your system.

What We Like
Easy filter replacement
Clear fuel quality visibility
Self-venting drain feature
Optimizes engine performance
#TOP 4

Caterpillar Fuel Water Separator

CAT
175-2949
Pack of 1
Caterpillar Fuel Water Separator Cover
Caterpillar 175-2949 Advanced High Efficiency Fuel Water Separator

The Caterpillar 175-2949 Advanced High Efficiency Fuel Water Separator is a genuine CAT product designed to remove water and other impurities from your vehicle's fuel system. With a thread size of 1-14, a height of 185mm, and a diameter of 93mm, it is specifically designed to fit your vehicle. This modern-style fuel water separator is an essential component of your vehicle's fuel system that helps to prevent engine damage, improve fuel efficiency, and reduce emissions.

What We Like
Genuine CAT product
Designed to remove water and impurities from fuel system
Improves fuel efficiency, reduces emissions
#TOP 5

iFJF FS1098 Fuel/Water Separator

FS1098
Pack of 1
iFJF FS1098 Fuel/Water Separator Cover
iFJF FS1098 Fuel/Water Separator with PCV Valve Replacement for B6.7 ISB6.7/QSB6.7 ISL8.9 L9 Series Diesel Engines for 5308722 5319680(Pack of 6)

The iFJF FS1098 Separator is designed specifically for B6.7 ISB6.7/QSB6.7 ISL8.9 L9 Series Diesel Engines, ensuring optimal performance. Its hydraulic spin-on filter provides excellent filtration efficiency, helping to keep your engine clean and running smoothly. The advanced StrataPore and NanoNet technology in the fuel filters delivers top-notch quality, enhancing fuel cleanliness and engine longevity. Additionally, filling the filter with fuel before installation prevents dry starts, ensuring a hassle-free setup. This product is a reliable choice for anyone looking to maintain their diesel engine effectively.

What We Like
High filtration efficiency
Advanced filtration technology
Easy installation process
Engine longevity support
#TOP 6

iFJF 802893Q01 Fuel Water Separator Kit

iFJF-WSFF02
1pcs
iFJF 802893Q01 Fuel Water Separator Kit Cover
iFJF 802893Q01 Fuel Water Separator Kit 10 Micron 18-7983-1 Filters for Replacing Mercury 35-807172 35-60494-1 18-7944 Marine 35-55501 35-57250 35-806771 35-802893T 35-802893Q ABB-FUELF-IL-TR

The iFJF Fuel Water Separator is designed to enhance the performance of your marine engine. With 10-micron filters that boast over 90% efficiency, you can trust that harmful particles will be effectively removed, protecting your fuel injection systems from damage. It flows at 90 gallons per hour, ensuring that even the most demanding motors receive the fuel they need without interruption. Remember to tighten the filter during installation for optimal performance. This kit is a reliable replacement for various Mercury models, making it a versatile choice for boat owners.

What We Like
High filtration efficiency
Fast fuel flow rate
Protects fuel systems
Compatible with multiple models
#TOP 7

Fleetguard Fuel Water Separator FS19765

Fleetguard
FS1976500
Fleetguard Fuel Water Separator FS19765 Cover
6/PACK FLEETGUARD FUEL WATER SEPARATOR FS19765

The Fleetguard Fuel Separator is designed to efficiently remove water and contaminants from fuel, ensuring optimal engine performance. This product is compatible with various applications, including Baldwin and Davco models, making it a versatile choice for different machinery. By using this separator, you can prevent fuel-related issues that could lead to costly repairs. It helps maintain the integrity of your engine by filtering out impurities, which can prolong its lifespan and enhance efficiency. With the Fleetguard Fuel Separator, you can enjoy peace of mind knowing your fuel system is protected.

What We Like
Effective water removal
Compatible with multiple applications
Improves engine performance
Enhances fuel system protection
#TOP 8

ZTUOAUMA Fuel Filter Kit

ZTUOAUMA
ZTUOAUMA Fuel Filter Kit Cover
ZTUOAUMA Fuel Water Separator Assy Bronze Fuel Filter Element Kit 6mm Outlet and Inlet with Hoses and Clamps Compatible with Webasto Eberspacher Diesel Parking Heaters

The ZTUOAUMA Fuel Filter is designed for Eberspacher and Webasto diesel parking heaters, ensuring a seamless replacement process. With a 6mm inlet and outlet diameter, it easily fits your existing setup. The filter features a bronze element that effectively captures dirt and rust particles, helping to maintain the cleanliness of your fuel system. Its waterproof material and transparent cover allow you to easily check for trapped debris, giving you peace of mind about fuel quality. Plus, it comes with all necessary clamps and hoses, making installation a breeze.

What We Like
High-efficiency bronze filter
Easy installation with included parts
Transparent cover for easy monitoring
Compatible with popular heater models
#TOP 9

Caterpillar Fuel Water Separator 256-8753

CAT
2568753
Pack of 1
Caterpillar Fuel Water Separator 256-8753 Cover
Caterpillar 2568753 Fuel/Water Separator, 1 Pack

Caterpillar Fuel Water Separator 256-8753 is an excellent choice for customers who need to separate fuel and water. With an efficiency rating of Advanced Efficiency, it can remove more impurities from fuel and water. As a primary filter, it is designed to protect the engine and prolong the lifespan of the fuel system. The separator has a diameter of 93.0 MM, which can fit most fuel systems. The exterior is painted, which makes it more durable and resistant to corrosion. The product is packed with one separator.

What We Like
Advanced Efficiency rating for better impurities removal
Primary filter design to protect the engine and prolong lifespan of fuel system
Painted exterior for durability and corrosion resistance
#TOP 10

WIX Filters - 33405 Heavy Duty Fuel Water Separator

Wix
33405
WIX Filters - 33405 Heavy Duty Fuel Water Separator Cover
WIX Filters - 33405 Heavy Duty Spin On Fuel Water Separator, Pack of 1

The WIX Filters - 33405 Heavy Duty Spin On Fuel Water Separator is a reliable and durable filter that features a pleated paper filter and a mesh support screening. It is designed to provide increased dirt and water removal, which makes it an ideal supplement filter. Its drain plug allows for easy draining of excess water from the filter. It is also very easy to install and maintain.

What We Like
Easy to install and maintain
Provides increased dirt and water removal
Reliable and durable
Buying Guide Image

Frequently Asked Questions (FAQs)

1. What function do fuel and water separators perform?

Fuel and water separators serve as an additional protection for your vehicle's fuel system. They filter out water and particulates from the fuel before it reaches the fuel filter, ensuring that only clean fuel flows to the engine. This helps prevent water contamination and potential damage to the engine.

2. Does fuel water separator work?

Yes, a fuel water separator is an essential component of a boat's fuel system. It effectively separates water and impurities from the fuel, ensuring smooth and efficient engine operation. It also helps to extend the life of the engine by preventing corrosion and damage caused by water and debris.

3. What happens if you don't change your fuel water separator?

If you fail to change or maintain your fuel water separator, water and other pollutants can mix with the fuel injector, potentially causing damage to the engine. Additionally, the check engine light may illuminate as an indication of a problem with the fuel water separator.

4. How often do you drain a fuel water separator?

It is recommended to drain water from the fuel water separator whenever the warning light illuminates or a message appears on the information display, indicating the need to drain the water separator. Typically, this occurs when approximately 6.76 fl oz (200 ml) of water has accumulated in the module assembly.

5. What are the disadvantages of oil water separator?

One disadvantage of an oil/water separator is that it only works effectively for oil-like substances that are water-insoluble or have a density similar to that of water. It may not function properly for oil in water emulsions, where the oil and water are thoroughly mixed. In such cases, alternative methods may be needed to separate the oil from the water.

Editor's Notes

During our fuel & water separator research, we found 24 fuel & water separator products and shortlisted 10 quality products. We collected and analyzed 11,513 customer reviews through our big data system to write the fuel & water separators list. We found that most customers choose fuel & water separators with an average price of $25.38.

The fuel & water separators are available for purchase. We have researched hundreds of brands and picked the top brands of fuel & water separators, including CARMOCAR, Sierra, CAT, iFJF, Fleetguard. The seller of top 1 product has received honest feedback from 366 consumers with an average rating of 4.7.

Written by
Robert Reyes Avatar

Robert Reyes is a dedicated writer from San Francisco with a bachelor of degree in mechanics and a bachelor of degree in marketing. He focuses on making some complicated topics simple and enjoys explaining complex and technical things in an easy-to-understand way.