from Hacker News

SKYACTIV-X: first commercial gasoline engine to use compression ignition

by interconnector on 8/8/17, 3:58 PM with 232 comments

• by ChuckMcM on 8/8/17, 5:34 PM

  A reuters story on how it works: https://www.reuters.com/article/us-mazda-strategy-idUSKBN1AO...

  So this is 'gasoline' diesel. Or diesel without the NOx. Which, in theory, would give better fuel economy and possibly better torque. And it will ship in cars in the 2019 model year (so possibly as early as late next year).

  To me, it sounds like a "Don't pass"[1] bet on electric cars. Which they also are working with Toyota on electric cars so perhaps it is a fall back plan. It will be interesting to see how it fares. There are a lot of products that are built as the other side of an industry change bet. Sun created a workstation on the 68040 in case the SPARCStation didn't meet expectations as an example.

  [1] In the dice game Craps, the "Don't Pass" bet is against the current player 'winning.'

• by Danihan on 8/8/17, 5:18 PM

  >Compression ignition and a supercharger fitted to improve fuel economy together deliver unprecedented engine response and increase torque 10-30 percent over the current SKYACTIV-G gasoline engine.*3

  Wow. I already have a 2016 Mazda 3 that gets around 40MPG (even though it's not a hybrid) and it's already pretty peppy.

  Probably the best car I've owned, and I've owned several nice sports sedans. Getting 40MPG is too convenient when you make longer commutes, not to mention the thing cost ~20k at 0% APR. Blows any hybrid out of the water for total COO.

• by lini on 8/8/17, 7:06 PM

  Mercedes Benz introduced something very similar to this ten years ago[1]. The engine was using HCCI at low RPM and conventional spark-plug ignition at higher RPM.

  [1] https://en.wikipedia.org/wiki/DiesOtto

• by stirkac on 8/8/17, 5:18 PM

  Mazda is one of those companies just don't stop revolutionizing. First they got rotary to be actually usable. Now this.

• by userbinator on 8/9/17, 12:37 AM

  I consider the headline slightly misleading, since compression ignition engines that run on a variety of fuels, including gasoline, were relatively popular around the turn of the century:

  https://en.wikipedia.org/wiki/Hot-bulb_engine#Advantages

  Another big attraction with the hot-bulb engine was its ability to run on a wide range of fuels. Even poorly combustible fuels could be used, since a combination of vaporiser- and compression ignition meant that such fuels could be made to burn. The usual fuel was fuel oil, similar to modern-day diesel fuel, but natural gas, kerosene, crude oil, vegetable oil or creosote could also be used.

  Also known as "semidiesels".

• by maerF0x0 on 8/8/17, 6:07 PM

  I think this is a great step forward for ICE . Combining this technology into generators (and cars like chevy volt) will make an extremely convenient and fuel efficient vehicle.

• by pedrocr on 8/8/17, 6:36 PM

  Technologies are always at their best when they're already being obsoleted. Just as electric cars become practical ICEs are getting great and so are the transmissions, making for great modern powertrains.

  There were rumors last year in F1 that one of the manufacturers was doing HCCI for it's engine (the same that Mazda has done here). I don't think any actually did but Ferrari did introduce a jet ignition system[1] that allows them to run much leaner. I wonder if anyone is thinking of adapting that to normal road cars.

  [1] http://www.motorsportmagazine.com/opinion/f1/ferraris-formul...

• by IgorPartola on 8/8/17, 5:27 PM

  So how exactly does this work? And why is it more effective and how does it allow you to run super lean while producing the same amount of power? Also, presumably running lean would mean lower emissions, but is that really true?

• by elihu on 8/8/17, 6:33 PM

  Maybe this is old news to people who pay attention to car news, but the most interesting thing to me is this line from the press release:

  > From 2019, start introducing electric vehicles and other electric drive technologies in regions that use a high ratio of clean energy for power generation or restrict certain vehicles to reduce air pollution

  I've been kind of disappointed that Mazda hasn't gotten into the electric car market yet; I'm glad to see they're coming around.

• by devy on 8/8/17, 6:59 PM

     SKYACTIV-X is the world's first commercial gasoline engine to use compression ignition, in which the fuel-air mixture ignites spontaneously when compressed by the piston.
  

  Just pure curiosity, I wonder if SKYACTIV-X engine would also also consume diesel or gasoline/diesel mixtures?

• by grondilu on 8/9/17, 6:25 AM

  A nice YouTube video about what this is about:

  https://www.youtube.com/watch?v=OVWZFdb_AGc

• by rbanffy on 8/8/17, 5:26 PM

  How much more R&D can the internal combustion engine pay for?

• by rsync on 8/8/17, 8:35 PM

  Can we please get somebody to create:

  blahblah-notelectric-blahblah.blogspot.com ?

  Then you can just collect all of these late stage ICE optimization press releases in one place.

  And we can ignore them.

• by ajross on 8/8/17, 5:28 PM

  Gah, terribly confusing terminology. This is a Diesel engine. "Compression ignition" is what the Diesel cycle is all about. It's just carefully tuned such that it can run on gasoline instead of kerosene (i.e. "diesel fuel").

  And mostly I don't get it. This is just a convenience factor. If you want a high-efficiency diesel right now you can buy one already. Low-volatility fuels are already more energy-dense (i.e. fewer losses carrying the stuff around in the tank) and require less energy to refine. This gives you the advantage of being able to pull into a gas station without diesel available, but otherwise doesn't seem to add much.