
63Types and Properties of Lubricating Oils
can also provide an indication of the potential stability or reactivity of the oil as the
double bonds in the olens make these generally more reactive than the saturated
parafns, particularly when exposed to oxygen in the air.
2.4.11 aPi luBricant Base stOck Oil grOuPs
The lubricating oil base stocks are divided into groups by the API, as shown in
Table 2.1. Groups II+ and III+ are not formal API groups, but the lubricants indus-
try often makes use of these additional categories to distinguish an oil with better
performance.
2.4.12 additives tO Base stOck Oils
The base stock components in the lubricati ...