Comparison of audible and digital techniques for the determination of gasoline octane rating in production engines

A microprocessor-based knock measuring system has been developed and tested for use in fuel rating and octane rating increase tests. Tests have been c onducted with eight knock raters, and this has shown inter-rater and intra- rater variability. It has also been shown that there is no absolute standar d by which knock can be measured. However, it has been argued that, as long as a consistent measuring system is used, comparative fuel testing can be undertaken with greater repeatability by using the microprocessor-based kno ck detector.