Federal law mandates that all United States passenger car gasoline engines be equipped with crankcase and exhaust emission devices in 1968. These devices, combined with increased short-trip stop-and-go driving under extended oil drain periods, likely will challenge the performance properties of motor oils. Interim results from various field and laboratory tests show that motor oils are available to meet the expected needs of 1968 engines provided the oils are drained more frequently as engine mileage accumulates.
The MS sequence tests were found to be reliable laboratory test tools to screen motor oils prior to field testing. As experience accumulates with 1968 engines, continued surveillance by both the automotive and petroleum industries is recommended to keep engine requirements and motor oil qualities in tune with each other.