Mazda Announces It Has Solved Gasoline’s Pre-ignition Problem with High Compression

I wonder where spark ignition comes in with Mazda's technology? Compression ignition for the long haul and overall efficiency; spark ignition for edge conditions that require a little "cheat?" Just thinking out loud...

 

Will they be able to do "super lean burn" without excessive NOX emissions ? Will the supercharged version be efficient ? Or just powerful ? And screw the CX-5 , can we have a 1.5L version in a 3 ? Okay, I know I'm asking for a lot. But they seem to be promising a lot (20-30% more efficient than SKYACTIV-G). This could be a good thing. You brought up a number of other good questions ; hopefully Mazda engineers are as good as I think they are.

 

This is really exciting! I remember reading about Honda's experiments with compression ignition 2-stroke motorcycle engines around the turn of the century. Apparently those efforts stalled because of the very small window of load and rpm that the system worked. As I google around I'm reading that Skyactiv-X uses spark ignition at higher loads and compression ignition at lower loads. Just the opposite of what I expected. I also read that the engine may debut in the next generation Mazda3 due in late 2018. That would be awsome! The end of the filthy diesel engine is near and it can't come soon enough, IMO!

 

Here's a good overview of the technology with reports on progress by various automakers:

https://www.just-auto.com/analysis/briefing-hcci-engine-technology_id174273.aspx

 

From the article Jay referenced...

I like the sound of that!

 

from the link above. This gasoline compression engine technology is really the holy grail of internal combustion. If Mazda has a practical engine--GO MAZDA!

 

3 year old C&D article says they won't downsize HCCI because they can't flow enough air, .... but then again, I don't see the word "supercharger" mentioned in the article either ...

"Surprisingly, Mazda is passing on today’s popular trend of downsized, turbocharged engines—say, a 1.4-liter turbo instead of this 2.0-liter. The company says the next generation of gasoline engines, which will employ HCCI (Homogenous Charge Compression Ignition)—essentially firing a gasoline engine like a diesel, without using the spark plugs—will erode the benefits of downsized engines. Smaller engines reduce pumping losses by operating at a higher load (the throttle is open further) more often. In the same way, HCCI engines will have to flow more air to realize the fuel-saving, lean-combustion benefits of that cycle. Mazda claims that if it downsized the Sky family of engines they wouldn’t be able to flow enough air for HCCI without upsizing once again. Plus, as Mazda rightly points out, adding a turbocharger and an intercooler is quite a pricey proposition."
http://www.caranddriver.com/news/mazda-skyactiv-g-and-skyactiv-d-engines-news

//I'm guessing an HCCI Mazda3 wouldn't necessarily "leap frog" over Honda's 1.5t civic, ... but it might step past it.

 

A guess (using the 20% to 30% increase), ... maybe a 2019 Mazda 3 with a HCCI(ish) 2.0 engine could turn in EPA ratings of 32/45/38 ?

 

Mazda's own press release today regarding Skyactive X says the engine will have a supercharger fitted:

http://www2.mazda.com/en/publicity/release/2017/201708/170808a.html

Of course, that could always change

 

EPA Tier 2 Bin 5 NOx limit is 0.07 grams/mile. Euro 6 limit is 0.08 g/km or about 0.13 grams/mile.

EPA Tier 3 regulations, which are currently being phased in, combines NOx and NMOG into a single emission category (NMOG+NOx). So the equivalent of T2B5 is T3B160.

 

I found this youtube video of a powerpoint presentation given by Mazda president and CEO, Masamichi Kogai and director and senior managing officer, Kiyoshi Fujiwara. The presentation outlines the direction and focus of Mazda's short, medium, and long-term plans, including Skyactive X technology. Fujiwara-san describes Skyactive X technology in detail beginning at about minute 25. The presentation is in Japanese with English subtitles:

The Skyactive X presentation describes the advantages of gasoline controlled compression ignition vs spark ignition and the technical problems of achieving CCI. Some of the important takeaways:

• Mazda solved the problem of achieving CCI over a wide range of rpm and load by using the spark plug to ignite a small area of fuel near the plug which acts as a piston to initiate CCI.
• Spark ignition (SI) air-to-fuel ratio must be about 14.7:1 for the flame front to propagate. CCI air-to-fuel ratio is 36.8:1 (!)
• Mazda claims CCI combustion over the full range of rpm and loads. The only time they resort to SI is cold temperature warm up. They claim the change in operation between SI and CCI is seamless.
• Mazda uses a "highly responsive air supply unit" to send air into highly compressed cylinders. I can't tell from the illustration if it is a supercharger or turbocharger. The unit expands the range of CCI.

 

For those that want to better understand this technology, I found this explanation really useful:

 

Spy shots are emerging of the new Skyactiv x Mazda3. That Mazda is testing a prototype in late stages of development gives me hope that Skyactiv x isn't vaporware that makes a big splash but never makes it to market. Go Mazda!

https://www.autoblog.com/2017/08/31/mazda3-skyactiv-x-engine-spy-shots/#slide-7074526

 

I like the matte paint look. Wonderful things they do with wraps.

 

Like Mazda and Honda diesel cars.

 

yes.

In June I finally made a decision to buy a new Honda Civic hatchback. Honda, for some reason, is trying their best to drive customers away from the 6MT and to the CVT. Their primary tactic is to not make enough 6MTs to satisfy demand. They make 6MT customers order one and then wait many months for delivery. I put my deposit down but insisted on a back-out clause if it doesn't arrive in 3 months. Oct is my due date and it doesn't look hopeful that my car will get here. I'm thinking seriously of opting out. I'm frustrated and angry at Honda for making me wait. I still like my current car, and this Mazda...wow! I would definitely hold onto my current car for another year if there's a good chance Mazda comes through with Skyactiv x as promised. Go Mazda!