TITLE

MOTOR OIL GUIDE

part 3

API Symbol Use & Definition

CD (obsolete)(Severe Duty Diesel Engine Service) Service typical of supercharged diesel engines in high speed, high output duty requiring highly effective control of wear and deposits. Oils designed for this service were introduced in 1955, and provide protection from bearing corrosion and from high temperature deposits in supercharged diesel engines when using fuels of a wide quality range.

CD-11 (obsolete) (Two-Stroke Diesel Engine Service) Service typical of two-stroke cycle diesel engines requiring highly effective control over wear and deposits. Oils designed for this service also meet all performance requirements of API Service Category CD.

CE (obsolete) (Turbocharged or Supercharged Heavy Duty Diesel Engine Service) Service typical of turbocharged or supercharged heavy duty diesel engines manufactured since 1983 and operated under both low-speed, high-load and high-speed, high-load conditions. Oils designed for this service may also be used when previous API engine service categories for diesel engines are recommended.

CF (indirect Injected Diesel Engine Service) This Category denotes service typical of indirect injected diesel engines, and other diesel engines which use a broad range of fuel types including those using fuel with higher sulfur content, for example, over 0.5% wt. Effective control of piston deposits, wear and copper-containing bearing corrosion is essential for these engines which may be naturally aspirated, turbocharged or supercharged. Oils designated for this service have been in existence since 1994. Oils designated for this service may also be used when API service category CD is recommended.

CF-2 (Two Stroke Cycle Diesel Engine Service) This Category denotes service typical of two-stroke cycle engines requiring highly effective control over cylinder and ring-face scuffing and deposits. Oils designated for this service have been in existence since 1994 and may also be used when API Service Category CD-his recommended. These oils do not necessarily meet the requirements of CF or CF-4 unless passing test requirements for these categories.

CF-4 (1990 Diesel Engine Service) This category was adopted in 1990 and describes oils for use in high-speed, four-stroke-cycle, diesel engines. API CF-4 oils exceed the requirements of the CE category providing improved control of oil consumption and piston deposits. These oils should be used in place of CID oils. They are particularly suited for on-highway, heavy duty truck applications. When combined with the appropriate "5" category, for example SG, they can also be used in gasoline and diesel powered personal cars such as automobiles, light trucks and vans when recommended by the car or engine manufacturer.

CG-4 (Severe Duty Diesel Engine Service) This Category describes oils for use in high-speed four-stroke cycle diesel engines used on both heavy-duty on-highway (less than 0.05% wf. sulfur fuel) and off highway (less than 0.5% wt. sulfur fuel) applications. CG-4 oils provide effective control over high temperature piston deposits, wear, corrosion, foaming, oxidation stability and soot accumulation. These oils are especially effective in engines designed to meet 1994 exhaust emission standards and may also be used in engines requiring API Service Categories CID, CE and CF4. Oils designated for this service have been in existence since January 1995.

API Symbol	Use & Definition
CD (obsolete)(Severe Duty Diesel Engine Service)	Service typical of supercharged diesel engines in high speed, high output duty requiring highly effective control of wear and deposits. Oils designed for this service were introduced in 1955, and provide protection from bearing corrosion and from high temperature deposits in supercharged diesel engines when using fuels of a wide quality range.
CD-11 (obsolete) (Two-Stroke Diesel Engine Service)	Service typical of two-stroke cycle diesel engines requiring highly effective control over wear and deposits. Oils designed for this service also meet all performance requirements of API Service Category CD.
CE (obsolete) (Turbocharged or Supercharged Heavy Duty Diesel Engine Service)	Service typical of turbocharged or supercharged heavy duty diesel engines manufactured since 1983 and operated under both low-speed, high-load and high-speed, high-load conditions. Oils designed for this service may also be used when previous API engine service categories for diesel engines are recommended.
CF (indirect Injected Diesel Engine Service)	This Category denotes service typical of indirect injected diesel engines, and other diesel engines which use a broad range of fuel types including those using fuel with higher sulfur content, for example, over 0.5% wt. Effective control of piston deposits, wear and copper-containing bearing corrosion is essential for these engines which may be naturally aspirated, turbocharged or supercharged. Oils designated for this service have been in existence since 1994. Oils designated for this service may also be used when API service category CD is recommended.
CF-2 (Two Stroke Cycle Diesel Engine Service)	This Category denotes service typical of two-stroke cycle engines requiring highly effective control over cylinder and ring-face scuffing and deposits. Oils designated for this service have been in existence since 1994 and may also be used when API Service Category CD-his recommended. These oils do not necessarily meet the requirements of CF or CF-4 unless passing test requirements for these categories.
CF-4 (1990 Diesel Engine Service)	This category was adopted in 1990 and describes oils for use in high-speed, four-stroke-cycle, diesel engines. API CF-4 oils exceed the requirements of the CE category providing improved control of oil consumption and piston deposits. These oils should be used in place of CID oils. They are particularly suited for on-highway, heavy duty truck applications. When combined with the appropriate "5" category, for example SG, they can also be used in gasoline and diesel powered personal cars such as automobiles, light trucks and vans when recommended by the car or engine manufacturer.
CG-4 (Severe Duty Diesel Engine Service)	This Category describes oils for use in high-speed four-stroke cycle diesel engines used on both heavy-duty on-highway (less than 0.05% wf. sulfur fuel) and off highway (less than 0.5% wt. sulfur fuel) applications. CG-4 oils provide effective control over high temperature piston deposits, wear, corrosion, foaming, oxidation stability and soot accumulation. These oils are especially effective in engines designed to meet 1994 exhaust emission standards and may also be used in engines requiring API Service Categories CID, CE and CF4. Oils designated for this service have been in existence since January 1995.