Bridging the GF-4 timing gap--an additive industry perspective. (ACC Update).(Brief Article)

Passenger car engine oil specifications have historically evolved in step with engine design changes, while also accommodating the needs of older vehicles. This technically prudent, tried-and-true method of updating engine oil specifications served the industry well when engine technology changes were the major driver of oil quality standards--but times have changed.

Over the past decade, oil specifications have been driven mainly by environmental regulations, such as fuel economy requirements and emissions reductions. This fundamental change has caused the objective of new oil specifications to shift from engine protection to environmental protection--a trend that could shorten the lifespan of older cars unless the new oils are tested …