RESULTS of the 1953 CRC survey of octane-number requirements are presented in this paper. This 1953 survey initiated the use of a new technique, which included both full- and part-throttle procedures.
Nine new-design models, represented by 235 cars, were tested using primary reference fuels, severity reference fuels, and a series of full-boiling-range gasolines.
It differed from the previously used technique in that accelerations were made at a series of constant intake manifold vacuums from 10 in. of Hg to wide-open throttle.