MerCruiser is a company that offers sterndrive and inboard engines for boats with horsepower ranging from 135 to 430. The MerCruiser brand has carbureted TKS models and also MPI fuel injected models, such as the 5.0L MPI engine. There are three MerCruiser models that require gasoline, including the 3.0L Alpha One and the 502 Magnum Bravo.
Recommended Oil Types
Mercury Marine, the manufacturer of the MerCruiser 454, recommends Mercury MerCruiser Full Synthetic Engine Oil 20W-40 NMMC FC-W for the engine. When the air temperature is less than 0 degrees Celsius, which is equivalent to less than 32 degrees Fahrenheit, SAE 20W crankcase oil should be used for MerCruiser engines. In air temperatures of 0 degrees to 10 degrees Celsius -- which is equivalent to 32 to 50 degrees Fahrenheit -- SAE 30W oil should be used. If air temperatures are above 50 degrees Fahrenheit or 0 degrees Celsius, SAE 40W oil is recommended. perfprotech.com recommends Quicksilver oil with a rating of 25W-40, 20W-40 or 20W-50.
Oil Types to Avoid
It is not recommended that synthetic, non-detergent oil, oil of multiple viscosity, oil with additives or any low quality oil is used for MerCruiser products, according to Performance Product Technologies.
Oil Capacity
Read the Operation, Maintenance, Warranty and Service manuals to determine what the capacity of oil should be for each particular MerCruiser crankcase. The MCM 60 requires 2.75 quarts of oil. MerCruiser models that require 4 quarts of oil are the MCM 110, 120 and 140, the MCM 1.3L and MPI and the Ski 5.7L. The MCM 175, 185 and 205, the 262 MAG EFI, MCM 4.3L, LX, LH and LXH, MCM 4.3L EFI, MCM 5.0L and MPI, MCM 350 MAG, EFI and MPI, and MIE 5.7L, 350 MAG MPI models after 2002 require 4.5 quarts of oil.