MerCruiser Emissions FAQs

How can I find my closest authorized MerCruiser dealer?

Authorized MerCruiser dealers in the United States and Canada can be found under Find a Dealer on this website.

Links to regions outside of the United States and Canada can be found on the Contact Us page.

What determines if an engine must have catalytic converters?

A mandate from the California Air Resources Board (CARB) stipulates that, beginning in 2008, any engine sold in the state of California must achieve a combined 75 percent reduction in hydrocarbons and nitrogen oxides. The only way to reach that emissions level is to fit the engines with catalytic converters. Any engine with a manufactured date on or after January 1, 2008, to be sold in the state of California must have catalytic converters. The one exception to this rule is 4.3L engines, which are covered by an exemption. Engines sold in California must be CARB-certified. For more information, visit the CARB (California Air Resources Board) Web site at http://www.arb.ca.gov/homepage.htm.

If an engine is CARB-certified in California, it can be sold in California.

Engines purchased for the purpose of repower replacement are required to meet the current regulatory requirements unless it is not possible to replace the existing engine with a catalyzed engine.  In this case the replacement engine can be equivalent to the existing engine; documentation is required in the event of repower with an engine that is not catalyzed.

As of January 1, 2010, the U.S. Environmental Protection Agency requires a Super-Ultra-Low 4-Star Emission (equipped with catalytic converters) engine for new sterndrive and inboard gas engines in all 50 states. 

Exempted Engines:

  • All 4.3L TKS & 4.3L MPI 3-star engines can continue to be sold into all 50 states until January 1, 2011.
  • 496 & 8.1 non-EC engines for 49 states excluding California.

For more information, visit the Environmental Protection Agency Web site at http://www.epa.gov/otaq/marinesi.htm

Can I register my boat outside of California if I live in California?

Yes, vessels currently and lawfully numbered (registered) by another state that are principally used outside California do not need to be registered in California.  California registration requirements and instructions are located at the following website:  http://www.dmv.ca.gov/boatsinfo/boat.htm

If I live in another state and buy a boat without a catalytic converter-equipped engine, can I use that boat in California?

Yes, you can use your boat in California as long as your boat is registered in another state. For more information, visit the California Air Resources Board Web site at http://www.arb.ca.gov/homepage.htm.

If I register my boat after January 1, 2008, in California, does it have to have a catalytic converter-equipped engine?

If the engine was manufactured before January 1, 2008, or if it is a 4.3L model, you are not required to have a catalytic converter. For more information, visit the California Air Resources Board Web site at http://www.arb.ca.gov/homepage.htm.

What engines are going to be catalyzed starting January 1, 2008?

Every MerCruiser engine, under 500 horsepower, for sale in California will be catalytic converter-equipped - except for the 4.3L and 4.3L MPI, which are covered by an exemption. For more information, visit the California Air Resources Board Web site at http://www.arb.ca.gov/homepage.htm.

What engines are going to be catalytic converter-equipped starting January 1, 2010?

Every MerCruiser engine, under 500 horsepower, for sale in the 49 states (except for California), will be catalytic converter-equipped  - except for the 4.3L and 4.3L MPI, which are covered by an exemption. For more information, visit the Environmental Protection Agency Web site at http://www.epa.gov/otaq/marinesi.htm

If I buy a boat from a dealer in late 2008 and it has engines without catalytic converters, can I use that boat in California?

If the engines were manufactured before January 1, 2008, you can use that boat in California. For more information, visit the California Air Resources Board Web site at http://www.arb.ca.gov/homepage.htm.

If I move into California with a 2008 or later engine without catalytic converters, can I register or use that boat in California?

There could be penalties associated with registering a boat without a catalytic converter-equipped engine. The boat may be registered in California if the owner can certify that at the time of purchase the owner was a resident of another state and the boat was registered in another state.  For more information, visit the California Air Resources Board Web site at http://www.arb.ca.gov/homepage.htm.

If I purchase a remanufactured engine, does it have to be equipped with catalytic converters?

A remanufactured engine must be rebuilt to its original state. For California, if the original engine was manufactured before January 1, 2008, it is not required to be catalyzed. For more information, visit the California Air Resources Board Web site at http://www.arb.ca.gov/homepage.htm.

For EPA guidelines, if the original engine was manufactured before January 1, 2010, it is not required to be equipped with catalytic converters. For more information, visit the EPA Web site at http://www.epa.gov/otaq/marinesi.htm

What components are considered emission-related and covered under the 3-year warranty? What are the specific terms of this warranty?

Certain emissions control parts are covered specifically by the California Emissions Limited Warranty and EPA Emissions Limited Warranty and are warranted for 3 years or 480 hours of operation, whichever occurs first.

Specific components covered under this warranty include:

  • Fuel metering system
  • Air induction system
  • Ignition system
  • Lubrication system components
  • Crankcase ventilation system
  • Exhaust system
  • Catalyst or thermal reactor systems
  • Miscellaneous items – for example hose clamps

Maintenance items are not included, such as:

  • Oil
  • Filters
  • Spark plugs

A copy of the California Emissions Limited Warranty and EPA Emissions Limited Warranty will be included from the factory with each new engine manufactured. Refer to this warranty for specific details.

Are there special service or operating requirements that dealers or consumers should be aware of, such as special oils, fuels, winterizing procedures?

There are no changes to our current fuel requirements for engines without catalytic converters. General winterizing procedures are unchanged for catalytic converter equipped engines.

IMPORTANT: If you are operating an engine equipped with Emissions Control, be aware that some oils can damage the catalytic converters. Although many marine-grade lubricants allow for acceptable engine performance, some contain high levels of phosphorus. Long-term exposure to these high-phosphorus oils will damage the catalytic converter. Catalytic converter damaged by lubricants containing high levels of phosphorus may not be covered by the MerCruiser Limited Warranty.

To help obtain optimum engine performance and to provide maximum protection, we recommend using the following oil:

Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMA FC-W rated

If the Mercury MerCruiser Full-Synthetic, 20W-40 oil is unavailable, you can use the following lubricants, listed in order of recommendation:

IMPORTANT: If you are servicing a catalytic converter equipped engine, and the Mercury MerCruiser Full-Synthetic, 20W-40 oil is unavailable, you can still use these lubricants, listed in order of recommendation, but only for short periods of time.

  • Mercury/Quicksilver 25W-40 Synthetic Blend, NMMA FC-W–rated 4-cycle MerCruiser oil
  • Mercury/Quicksilver 25W-40, NMMA FC-W–rated 4-cycle MerCruiser oil
  • Other recognized brands of NMMA FC-W–rated 4-cycle oils
  • A good-grade, straight-weight detergent automotive oil per the operating chart below.

NOTE: We do not recommend non-detergent oils, multi-viscosity oils (other than as specified), non FC-W–rated synthetic oils, low-quality oils, or oils that contain solid additives.