Sierra 10W-30 FC-W 4-Stroke Catalyst Engine Oil, 1 Gallon - Part 18-9420CAT-3 (Mercury 92-8M0078626)

The Sierra 18-9420CAT-3 is a 1-gallon jug of 10W-30 FC-W 4-stroke catalyst engine oil, formulated to meet the requirements of modern 4-stroke recreational engines with or without catalytic converters. This oil is designed to protect against wear, heat, and deposit buildup in the demanding conditions that recreational 4-stroke marine engines operate under, helping maintain consistent lubrication performance across the operating range.

Packaged in a durable 1-gallon jug for easy pouring and storage, this catalyst oil is offered in a 10W-30 viscosity grade suited to a wide range of 4-stroke outboard and sterndrive applications. It carries a direct Mercury cross-reference number, making it a straightforward match for engines that call for that formulation. Each case ships with 6 gallon jugs, making it a practical option for shops, marinas, and boat owners who go through oil regularly.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-9420CAT-3
• Mercury Cross Reference Number: 92-8M0078626
• Oil Type: 10W-30 FC-W 4-Stroke Catalyst Engine Oil
• Container Size: 1 Gallon
• Container Type: Jug
• Case Quantity: 6
• Weight: 7.7 pounds
• UPC: 808282326104

Fitment

Formulated for modern 4-stroke recreational engines, with or without catalytic converters.

Replaces (OEM)

• 92-8M0078626

Frequently Asked Questions

What viscosity is the Sierra 18-9420CAT-3 engine oil? The Sierra 18-9420CAT-3 is a 10W-30 FC-W 4-stroke catalyst engine oil, packaged in a 1-gallon jug.

What engines is this oil designed for? This 10W-30 FC-W catalyst oil is formulated for modern 4-stroke recreational engines, with or without catalytic converters.

Does 18-9420CAT-3 have a Mercury equivalent part number? Yes, part 18-9420CAT-3 corresponds to Mercury number 92-8M0078626.

How much does a gallon of this oil weigh? A 1-gallon jug of the Sierra 18-9420CAT-3 catalyst engine oil weighs 7.7 pounds.

What size container does this oil come in? 18-9420CAT-3 is packaged as a 1-gallon jug, with 6 jugs per case.

Is this oil sold by the case? The 18-9420CAT-3 gallon jug ships in cases of 6; a corresponding pallet quantity is also available under a separate part number.

What is the UPC for this product? The UPC for the Sierra 18-9420CAT-3 10W-30 FC-W catalyst engine oil gallon is 808282326104.

Is this a synthetic oil? 18-9420CAT-3 is a conventional 10W-30 FC-W catalyst formulation; Sierra also offers a separate 25W-40 synthetic catalyst oil line.

What does FC-W mean on this oil? FC-W is the oil specification designation shown on the Sierra 18-9420CAT-3 label, indicating it meets the FC-W 4-stroke marine oil standard.

Are smaller or larger container sizes available? The 10W-30 FC-W catalyst oil formulation used in 18-9420CAT-3 is also offered in quart and 55-gallon container sizes under separate part numbers.