API SN Engine Oil Category

In 2010 the American Petroleum Institute introduced a new engine oil category under the name API SN and a new supplemental category called Resource Conserving.

The API SN category is an improvement over the API SM category in the following areas:

• High temperature deposit protection for pistons
• Better sludge control
• Better seal compatibility
• Aftertreatment compatibility

This means that API SN compares to API SM like this:

API SN and API SM comparison chart

The Resource Conserving supplemental category requires further properties. The former supplemental category, which was called Energy Conserving required only fuel saving properties from the oil. Resource Conserving requires further properties like:

• emission system protection
• turbocharger protection
• compatibility with engines operating on ethanol containing fuels, up to E-85

The requirements of API SN with the Resource Conserving supplemental category are identical to the requirements of the ILSAC GF-5 standard.

In order for an oil to meet the requirements of API SN or API SN/Resource Conserving it should satisfy the following test criterias:

	API SN		API SN + RC
Viscosity Grades	0W20, 0W30, 5W20, 5W30, 10W30	Others	Multigrade variations of 0W, 5W and 10W
Laboratory Tests
Sulphur, max %
0Wxx and 5Wxx	0.5	NR	0.5
10W30	0.6	NR	0.6
Others	NA	NR	0.6
High temperature deposits, max mg
TEOST MHT	35	45	35
TEOST 33C	NR	NR	0.6
Foam	1 min. settling	10 min. settling	1 min. settling
Gelation Index	12	NR	12
Emulsion Retention	NR	NR	No Water Separation
Seal Compatibility	ILSAC GF-5 limits apply
Phosphorous, max% / min%	0.08 / 0.06	NR / 0.06	0.08 / 0.06
Engine Tests
Sequence VID	NR	NR	Pass
ROBO or Sequence IIIGA	Pass	NR	Pass

Source: American Petroleum Institute

Check out our API Engine Oil Categories page for information about further API Oil Standards!