Sierra 10W-30 Catalyst Engine Oil, 1 Quart, Mercury 92-8M0078625 Equivalent (18-9420CAT-2)

Sierra 18-9420CAT-2 is a 10W-30 premium blend catalyst engine oil packaged in a 1 quart (946 ml) bottle. It is formulated for use in engines equipped with catalytic converters, and Sierra states these oils are designed to meet the unique requirements of modern 4-stroke recreational engines, with or without a catalytic converter. This makes it a suitable choice for boat owners who want a single oil that covers both catalyst-equipped and non-catalyst 4-stroke outboard and sterndrive engines without having to stock two different formulations.

The 10W-30 viscosity provides reliable lubrication and protection across a range of operating temperatures typical of recreational marine use. The oil is packaged in a convenient bottle for easy pouring during routine oil changes and top-offs. Sierra also cross-references this product to Mercury part number 92-8M0078625, so it can be used as a direct equivalent where that Mercury oil is specified.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-9420CAT-2
• Mercury Cross Reference: 92-8M0078625
• Viscosity: 10W-30
• Oil Type: Premium blend catalyst engine oil
• Volume: 32 fluid ounces (1 quart / 946 ml)
• Container Type: Bottle
• Weight: 1 pound
• UPC: 808282325961

Fitment

Designed for 4-stroke recreational marine engines, with or without a catalytic converter.

Replaces (OEM)

• 92-8M0078625 (Mercury)

Frequently Asked Questions

What size does the 18-9420CAT-2 come in? Sierra 18-9420CAT-2 is packaged as a 1 quart (946 ml) bottle of 10W-30 premium blend catalyst engine oil.

Is this oil safe for engines with a catalytic converter? Yes, this 10W-30 premium blend is a catalyst engine oil, formulated to meet the requirements of modern 4-stroke recreational engines with or without a catalytic converter.

What viscosity is Sierra 18-9420CAT-2? It is a 10W-30 viscosity engine oil, sold as a premium blend rather than a full synthetic.

Does this oil have a Mercury equivalent number? Mercury part number 92-8M0078625 corresponds to the same quart-size product as Sierra 18-9420CAT-2.

Can this oil be used in engines without a catalytic converter? Yes, the 18-9420CAT-2 formulation is designed to meet the requirements of modern 4-stroke recreational engines whether or not they have a catalytic converter.

Is Sierra 18-9420CAT-2 a full synthetic oil? No, it is labeled as a premium blend catalyst engine oil, not a full synthetic formulation.

What container does the oil come in? The 1 quart size of 18-9420CAT-2 is packaged in a bottle.

How much does a quart of 18-9420CAT-2 weigh? A 1 quart bottle of Sierra 18-9420CAT-2 weighs 1 pound.

Is 18-9420CAT-2 only available in a quart size? The quart (946 ml) bottle is one packaging option for this oil; it is also offered in other case and bulk configurations under related part numbers in the same catalyst oil line.

What is the UPC for this product? The UPC for the 1 quart Sierra 18-9420CAT-2 catalyst engine oil is 808282325961.