ANTIKNOCK REQUIREMENTS of Commercial Vehicles

THIS paper presents the results of a survey of the antiknock requirements of commercial vehicles.

The fuel requirements of commercial-vehicle and passenger-car engines were found to be quite similar on the basis of maximum requirement for knock-free operation. The commercial-vehicle engines have somewhat lower requirements at high speeds and tend to rate sensitive fuels slightly lower at high speed than do passenger-car engines at the same speeds.

Attention is drawn to examples of extreme maladjustment of ignition systems, and the effect of proper adjustment is shown. A wide variation in severity was found among commercial engines. It is indicated that this is not a function of size alone.