Comments by "David Elliott" (@davidelliott5843) on "Who's Got Better Fuel? Octane Ratings Explained and Mythbusted" video.

  1. European cars are specced on 97 octane gasoline. U.K. sells 95, 97 and 99 octane. Europe goes as low as 87. Engines avoid ignition knock by retarding ignition timing via a knock sensor. The fuel energy value is much the same at all octane levels. A high compression engine can make more power on high octane fuels. Low compression engines will not do any better on high octane fuels. My Fiat is as quick on 97 or 99 but feels flat on 95. It will run on 87 but feels like an 800cc town car. BMW 1200 boxer engines run on low octane but run a lot better on 97 or better. They feel flat on low octane because the later spark puts more heat down the exhaust.
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