1980 CRC Octane Number Requirement Survey.

In the 24th annual statistical survey of current model vehicles, test data were obtained on 429 1980 model vehicles, including 6 select models of special interest. Maximum octane number requirements under full- and part-throttle operating conditions were determined, and surface ignition knock and rumble, if present, were also reported. Passenger cars and light-duty trucks including non-commercial vans 12 - 34 ton without four-wheel drive were tested according to a weighted distribution. This years survey includes analyses for the following vehicle categories 1 U.S. and Imported Vehicles--429 vehicles 2 U.S. and Imported Cars--407 cars 3 U.S. Vehicles--334 vehicles 4 U.S. Cars--326 cars and 5 Imported Vehicles--85 vehicles. It should be noted that the term cars designates passenger cars only, while ther term vehicles includes passenger cars plus vans and light-duty trucks. The order of testing reference fuels was the same as the 1979 Survey, which is as follows Tank Fuel, High Sensitivity Full-Boiling Range Unleaded FBRSU Fuels, Average Sensitivity Full-Boiling Range Unleaded FBRU Fuels, and Primary Reference PR Fuels.