Introduction to the US Petroleum Institute (API) oil use range
For light duty diesel engines.
For use with premium fuels, diesel engines operating at light to medium loads, and sometimes for milder gasoline engines. However, it is no longer used except for the special recommendation of the automobile manufacturer.
Non-supercharged diesel engines for gasoline engines and low sulfur fuels.
For medium duty diesel engines.
For diesel engines operating at light to medium loads. High protection against engine wear and deposits. Sometimes used to run mild gasoline engines. For non-supercharged diesel engines that use high sulfur fuels, they have the property of preventing bearing corrosion and high temperature deposits.
Used in gasoline engines and non-supercharged diesel engines.
For medium duty diesel and gasoline engines.
Low-boost diesel engine for medium to heavy duty operation and includes some heavy duty gasoline engines. For low-boost diesel engines, this oil prevents high-temperature deposits; for gasoline engines, it prevents rust, corrosion and low-temperature deposits.
Low temperature to prevent sludge and rust, and has the performance required to adapt to low pressure diesel engines
For heavy duty diesel engines.
For high speed, high power supercharged diesel engines that require very efficient control of wear and deposits. Excellent and inferior fuel for supercharged diesel engines, which can effectively prevent bearing corrosion and high temperature deposits.
It has the performance required to adapt to the turbocharged diesel engine.
It is used for heavy duty supercharged medium-cooled diesel engines.
For new high speed, high power supercharged intercooled diesel engines that require very effective control of wear and deposits.
It has the performance required to adapt to heavy-duty supercharged intercooled diesel engines.
The S-series--the various levels in the gasoline engine oil series in turn reflect the different requirements for performance and structural development of the engine in different years.
The C-Series diesel engine oil range has evolved from CA, CB and CC, CD and CE grades, reflecting the enhanced performance of automotive diesel engines.