THIS paper deals with the road-test portion of the extensive efforts made during 1937 by the Cooperative Fuel Research Committee to get as precise a correlation as possible between the laboratory knock ratings of automobile fuels and their corresponding ratings in cars on the road. It is anticipated that the comprehensive results of car tests reported here, taken together with the results of the laboratory rating program reported in the companion paper, will serve as the basis of the continuing studies aimed at developing the best possible correlation between road and laboratory knock ratings.
Work similar to that reported here has been conducted concurrently in England by the Institution of Petroleum Technologists, using British cars and fuels. An exchange of information between the British and American groups working on this problem is being made. This commendable cooperation is indicative of the wide scope of these studies, and it is to be hoped that, as an outgrowth of this extensive cooperation, a solution will be found for the problem of making the laboratory ratings of motor fuels agree with ratings in cars which will be so satisfactory as to be universally acceptable.