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Compression ignition is being used in gasoline by Mazda. Their Skyactiv-X technology uses the spark to control when the compression ignites (like fake-dieseling

• legohead 8y ago
  I just got a new Mazda with a Skyactiv engine. I am really happy with the performance, but wanted to see about adding a turbo. Seems like it's not a good idea to add a turbo to an engine with 13:1 compression. The engine can actually run at 14:1, but they lowered it for the US. Anyway, Infiniti has a new engine that is variable-compression, so they can run at 14:1 OR 8:1, and they add on a turbo to use at the lower compression. Pretty freaking sweet: https://www.infinitiusa.com/about/technology/vc-turbo-engine.html https://www.infinitiusa.com/about/technology/vc-turbo-engine...
• stephengillie 8y ago
  Late edit: - Skyactiv uses the spark to control the compression-based ignition. - Skyactiv-X goes a step further to use only compression to ignite 87 octane gasoline.
• davidgould 8y ago
  It's really interesting to see Mazda take a lead in engine design. Once one would have expected this more from Honda. However, it's not all good. Apparently direct injection gasoline engines emit more particulates than conventional gasoline engines. This may be a manageable problem and new regulations are supposedly in effect from 2017 in the US (unless they got caught in Trumps emissions control rollback), but that does not clean up the several years of cars with direct injection before now.