An anti-knock agent is a gasoline additive that increases the temperature and pressure at which auto-ignition occurs. It helps to reduce engine knocking and raising the octane rating of the fuel.

While knocking is no longer as widespread a problem thanks to the current state of anti-knock sensor technology, it can be an issue for vehicles with gasoline direct-injection engines.

When you are buying gasoline with a particular octane number, joke's on you. There is little or no octane in there, because octane will blow you engine up. A little primer on anti-knock additives.

Charles K. Westbrook, William J. Pitz, William R. Leppard, The Autoignition Chemistry of Paraffinic Fuels and Pro-Knock and Anti-Knock Additives: A Detailed Chemical Kinetic Study, SAE Transactions, ...

America, by contrast, uses the average of the RON and the MON figures, called the AKI (anti-knock index). Thus, 97 octane “super unleaded” in Britain is roughly equivalent to 91 octane premium ...

"Addressing long-standing mysteries behind anti-wear motor oil additive." ScienceDaily. ScienceDaily, 13 March 2015. <www.sciencedaily.com / releases / 2015 / 03 / 150313130937.htm>.

Will octane additives fix the knocking sound if I put regular gas in a car requiring premium? LOU TROTTIER Special to The Globe and Mail Published December 14, 2016 ...