Honestly I would trade in my Speed3 for that, even if it doesn't get 250 hp. Really excited to see what Mazda can do with the SkyActiv-X engine.
SkyActiv-X Review, glimpse of possibly what to expect in future CX-5s
- Thread starter Xeler8ing
- Start date
Pure HCCI only really works in laboratory conditions. Optimize an HCCI engine for warm days and it will falter on cold days. Optimize it for cold, won't drive well in warm. Changing loads and driving styles also are hard.
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- 2021 CX-9 Sig
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- 2021 CX-5 GT
So, I found it. Actually it is in the Mazda zoom-zoom magazine. They say the new 2.0 in the Mazda 3 will give a 20% increase in fuel economy as compared to the 2.0 and give the Mazda 3 the same 0-60 time as the Miata (~5.8-6.0 seconds). That would be fantastic in a Mazda 3.
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- Plano, Texas, USA
Skyactive-X review and driving hands on
Does this mean I should wait for another 2~3 years getting a SkyActiv-X CX-5? (uhm)
I really really hope NOT!
Does this mean I should wait for another 2~3 years getting a SkyActiv-X CX-5? (uhm)
Prior to the spark the air/fuel mixture is driven to the threshold of compression ignition. The spark then ignites a small area and pushes the rest into compression ignition. The key innovation here is that the spark timing varies with ambient conditions that are measured and processed by the ECU.
For it to work the spark ignited area needs to be less lean than the rest of the cylinder. I suspect much the computational work is measuring and maintaining this.
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GJ-Molestor
Banned
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- 2011 BMW 528i, 2015 Mazda 6, 1995 Nissan Maxima Manual
exactly. Mazda said that several times they were about to give up on the idea all together. it was either they make a compromise (which they did so brilliantly) or the whole idea would just go to scrap.
think closer to mid 6 seconds
highly doubt they will. what's the point if the engine will already make good torque while also being fuel efficient at any RPM? it will work best and most efficiently with all four cylinders are firing.
Are you saying that the expansion of the ignited rich zone squeezes the remaining cylinder volume such that it compression ignites before the flame front would have propagated?
mazdadude
ZOOOOOOOOOM ZOOOOOOOOOM
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- '16.5 Mazda CX-5 Touring
Sometimes it will be using the sparkplugs, and at other times when conditions are optimal, it will be using compression ignition. The engine adjusts as required.
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- San Antonio, Texas
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- '15 CX-5 Miata AWD
merged and removed "first" from title
SkyActiv-X due 2019 or so for Mazda 3, 2020 and onwards for CX-5
EDIT: I think I figured it out
It's a lean burn engine - those have been around since the 70s - that solved one of the big problems of lean burn engines. Lean air/fuel burns slowly, so it only works under low load and RPM. Compression ignition on the other hand spontaneously ignites the whole mixture, but it's hard to control in a gasoline engine under real world use.
Mazda figure out that they can use a stratified charge, common in lean burn technology, where a rich mixture near the spark plug will ignite the rest of the cylinder that is lean. However they use that ignition to increase the pressure just enough that the rest spontaneously combusts rather than the traditional flame front combustion.. Apparently this used to be really hard to time the spark correctly for it to work and they solved that.
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I thought this was the case too from earlier descriptions, but the slideshow on this page shows it uses sparks all the time, altering the timing for load and ambient air situation. Looks like it uses a form of stratified charge that puts it in the ballpark of HCCI but is not HCCI.
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- 2021 CX-9 Sig
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- 2021 CX-5 GT
Even low to mid 6's would be good for the 3.
mazdadude
ZOOOOOOOOOM ZOOOOOOOOOM
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- '16.5 Mazda CX-5 Touring
Thank you for clarifying, I am going to have to go back and rewatch...lots to learn on this X motor. (uhm)
That was also my take from the slides I saw.
Apparently, it takes a lot to make this work: very high pressure direct injectors that can inject fuel later in the compression stroke and still produce a homogeneous charge, VVT, a supercharger to keep the mixture lean at higher rpm, an intercooler and an EGR cooler, and my favorite part is that they sample the cylinder pressure throughout each combustion cycle and compare it to a target curve. That's normally something you might do in the lab, but to use it in the control loop of a real vehicle is very cool.
This sounds like an expensive engine.
If it's something that people have thought of, but not implemented because its fussy and finicky, we'll have to see how well it works and how reliable it winds up being.
Funny how much of a fuss people are putting up over somethings as innocuous as cylinder deactivation, but the forum seems to be waiting for this new engine with baited breath.
If it pans out, I look forward to driving one of these when I'm done with my US diesel CX-5
Mazda tried to force rotary to be viable for a long time, despite obvious drawbacks.
Funny how much of a fuss people are putting up over somethings as innocuous as cylinder deactivation, but the forum seems to be waiting for this new engine with baited breath.
If it pans out, I look forward to driving one of these when I'm done with my US diesel CX-5
Mazda tried to force rotary to be viable for a long time, despite obvious drawbacks.
It's seems they took a bunch of engine technologies that had matured enough to be used in production (and perhaps patents had expired!) and then combined them with some novel ECU processing.
