Fuel/Oil Recommendation Frequently Asked Questions

What type of fuel can I use?

Model	Gasoline (Notes 2&3)	Additives
1987 and Newer: V8 350 cid, Except EFI Models. (Note 1) 1990 and Newer: 4 Cyl 181 cid, V8 454, & 502 cid, Except EFI Models. (Note 1) 1991 and Newer: V8 540 & 572 cid, Except Supercharged Models. (Note 1)	US/CAN - 87 (R+M)/2 98 RON minimum octane major brand of unleaded regular or premium without alcohol NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol (Note 4)	None Required
EFI: V8 350,454 & 502 cid. (Notes 1 & 5)	US/CAN - 87 (R+M)/2 minimum octane unleaded regular or premium without alcohol, DO NOT USE Leaded Gasoline NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol(Note 4)	None Required
V6 and All Other Older 4, 6 Cyl & V8 Models, Except Supercharged Models.	US/CAN - 87 (R+M)/2 minimum octane unleaded regular or premium without alcohol, DO NOT USE Leaded Gasoline NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol (Note 4)	A good-grade automotive valve lubricant
Black Scorpion models	S/N 0L005600 and below - DO NOT USE Leaded Gasoline US/CAN - 91 (R+M)/2 minimum octane unleaded regular or premium without alcohol NON US/CAN - 98 RON minimum octane major brand of unleaded regular or premium without alcohol S/N 0L005601 and above - DO NOT USE Leaded Gasoline US/CAN - 87 (R+M)/2 minimum octane unleaded regular or premium without alcohol NON US/CAN - 90 RON minimum octane major brand of unleaded regular or premium without alcohol	None Required
Supercharged Models	US/CAN - 92 (R+M)/2 minimum octane Unleaded premium without alcohol, DO NOT USE Leaded Gasoline NON US/CAN - 98 RON minimum octane Unleaded premium without alcohol (Note 4)	None Required

Can I use reformulated or oxygenated fuels?

The corrosion warranty is for three years from the original date of purchase of the complete power package for 1988 and newer MerCruiser product that have a one-year limited product warranty. See the complete corrosion warranty under the section titled Warranties or in your owner's manual. Protection against certain types of corrosion damage must be provided by using such systems as the Mercury Precision MerCathode system and/or galvanic isolator. These certain types of corrosion damage include damage due to stray electrical currents (on-shore power connections, nearby boats, submerged metal), etc. It is the owner's responsibility to ensure that all necessary anti-corrosion devices are in good working order and are providing adequate protection.

What type of oil should I use? Can I use synthetic oil?

To help obtain optimum engine performance and to provide maximum protection, we recommend the use of Mercury Precision 4-Cycle 25W-40 Marine Engine Oil. This oil is a special blend of 25-weight and 40-weight oils for marine engines. If not available, a good grade, straight weight, detergent automotive oil of correct viscosity, with an API service rating of SH,CF/CF-2 may be used. In those areas where Mercury Precision 4-Cycle 25W-40 Marine Engine Oil or a recommended straight weight oil is not available, a multi-viscosity 20W-40 or, as a second but less preferable choice, 20W-50, with API service ratings of SH,CF/CF-2 may be used.

IMPORTANT: The use of non-detergent oils, multi-viscosity oils (other than Quicksilver 25W-40 or a good quality 20W-40 or 20W-50), synthetic oils, low quality oils or oils that contain solid additives are specifically NOT recommended.

The table below is a guide to crankcase oil selection. The oil filter should always be changed with the engine oil.

AIR TEMPERATURE	Oil Type
All Temperatures	Mercury Precision 4-Cycle 25W-40 Marine Engine Oil
Below 32° F (0° C)	SAE 20W
32-50° F (0-10° C)	SAE 30W
Above 50° F (10° C)	SAE 40W

This crankcase oil recommendation supersedes all previously printed crankcase oil recommendations for MerCruiser gasoline engines. The reason for this change is to include the newer engine oils that are now available in the recommendation.

Older owner manuals, service manuals and other publications that are not regularly updated will not be revised to show this latest engine oil recommendation. Current owners manuals, service manuals and other service publications that receive regular updates will receive this revised recommendation the next time they are updated.