An Acceleration Based Method to Determine the Octane Number Requirement of Knock Sensor Equipped Vehicles

In vehicles equipped with knock sensors, it can be difficult to determine the octane number requirement according to the current Coordinating Research Council E-15 procedure which is based on detection of audible knock by trained raters. Therefore, a program was conducted to develop a new procedure which is more suitable for knock sensor equipped vehicles.

Due to adaptive actions taken by the electronic knock control system, the acceleration performance of a knock sensor equipped vehicle can be affected by fuel octane number. For the majority of vehicles tested, the acceleration time increased as fuel octane number was decreased. A promising new method was developed to determine vehicle octane number requirement based on acceleration performance.