Reuterssays part of the reason for the spark plug deals with low temperature combustion concerns, but in our earlier post on this topic, reader jariten. Mazda would go with a spark assisted system, saying My guess is that Mazdas engine is really a spark assisted HCCI engine that uses a regularish port or direct injection spark mode during transients, high load, or other non ideal conditions and only goes into HCCI during relatively steady state low load conditions cruising or idling when environmental conditions are within plannedmeasured parameters. In its release, Mazda does say the new tech offers high efficiency across a wide range of rpms and engine loads, and it would only make sense if that wide range covered normal, low load driving conditions that most of us see day to day. BibMe Free Bibliography Citation Maker MLA, APA, Chicago, Harvard. The latest travel information, deals, guides and reviews from USA TODAY Travel. Reader jariten. 17. HCCIs NOx emissions benefits, saying If theyve cracked the nut on HCCI it means lower NOx. The whole idea is that you have an airfuel mixture at just the right conditions that when the piston nears TDC you get simultaneous ignition everywhere. NOx contributor. While Im not an expert on homogenous charge compression engines, all of of this seems to makes sense. The more I read up on this tech, the more I get excited about its implementation in an actual production vehicle. Mazda will tell us more about their new engine tech before the Frankfurt Motor Show later this month, and Ill be there with a pen and a TI 8.