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Sierra 18-9440-4 25W-40 FC-W Synthetic Blend Marine Engine Oil - 5 Quart

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

118-9440-4
06/03/2036 10:18 AM
Sale Price

$39.72

In Stock (10+)

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Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

Sierra 18-9440-4 is a premium 4-stroke synthetic blend marine engine oil specifically formulated for the demanding conditions endured by sterndrive and inboard engines. This 25W-40 viscosity oil combines premium grade synthetic and mineral-based stock with advanced additives designed to maximize performance and extend engine life in modern high-horsepower marine applications.

Key Features:

  • NMMA FC-W Certified and API-SL rated for marine engine protection
  • Advanced lubrication reduces wear on internal engine components
  • Superior corrosion protection for harsh marine environments
  • Resists thermal breakdown under high RPMs, extreme temperatures, and heavy loads
  • Outstanding friction reduction and wear protection
  • Minimizes piston ring deposits for cleaner engine operation
  • 5 quart (4.73 liter) container

This synthetic blend oil is extensively tested to deliver outstanding performance in extreme marine conditions. Replaces Mercury 92-883725K01 and Mallory 9-82392. Cross-references include OEM part numbers 04189444, 29-7939, and 29-7940.

Fast shipping and great product. Great price. Will recommend you to others.

Seamless

It is the best

Quick delivery. Wish I could've ordered all my needed tv vent parts from you.

Easy to purchase, received my product rather quickly and on time.

Easy to find what I needed, killer price + reasonable shipping

Package shipped and arrived very quickly at a great price. Only suggestion would be to place the original packaging in an outer package as the box it arrived in appeared to be a little worn.

Very good and reliable service

Called to make sure it fit, ordered o line, great experience with ordering.

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