Really interesting facts about Skyactiv technology

[The Great NY]

Why wouldn't it be?

SkyActive 2.0 with HCCI is reportedly in the works.

http://wot.motortrend.com/1401_mazda_skyactiv_2_engines_to_feature_hcci_tech_debut_by_2020.html

Good question, Mazda took it seriously

The gas engines will achieve that extra efficiency with spark plug-less homogeneous charge compression ignition (HCCI) tech.

Read more: http://wot.motortrend.com/1401_mazd...re_hcci_tech_debut_by_2020.html#ixzz3kzXCkvTw

here is why i didnt take that question seriously. HCCI tech is far too costly to implement at a mainstream level. While making a statement saying its in the works, makes things sound good. it does not mean it's going to happen for a number of reasons.

Biggest issue is how hard it is to control an HCCI event. they are quite different than Diesels, although they say they are similar. only similarity is that it doesn't have spark ignition. Really thats where the similarity stops. Diesels work the way they due because the fuel injection can be actively timed by the injectors as fuel is injected into an already compressed air charge (top of the compression stroke almost. With HCCI the fuel and air enter the chamber at the same time, and ignite whenever the pressure and heat reach the proper point. Why is this an issue?

-Cold winters will make it SIGNIFICANTLY harder for the combustion to happen. sometimes not even happening at all. Hot summer days you will get early ignition. Weather temps effect HCCI greatly. Sure, heater and cooler assemblies could be implemented to help these issues, but that adds cost of another microcomputer along with other sensors and etc that are going to need to be added.

Valve actuation also effects HCCI greatly, along with quite a few other things. Also, HCCI due to the way it works operating on lean fuel mixtures, the peak temperatures are much lower than conventional gas and diesel engines. BUT, the low peak temperatures also lead to incomplete burning of fuel, especially near combustion chamber walls which leads to high carbon monoxide and hydrocarbon emissions.

Pre-ignition goes back to what i said about HCCI being hard to control when combustion happens. so pre-ignition will be harder to fight in an HCCI system. Also, although this seems to be where many Mazda is moving towards (doesn't mean i like it) HCCI engines have a small power range which is pretty much restricted to low loads by lean flammability limits and high loads by in-cylinder pressure restrictions

In short the overall complexity and issues fighting against the HCCI process, it will be quite tough to use HCCI engines in a mass produced cost effective way. As they are/will be far more expensive to build, engineer, and maintain than what we are currently using.

Also, Mazda is NOT the first people doing HCCI, GM had a running prototype back like 7-9 years ago i think it was. and there are other companies already attempting it. GM's version was a bit of a hybrid. but guess what, it only got 6 more MPG over the standard 2.2L Ecotec engine it replaced. Not worth the cost IMO. But this is just an educated opinion on my behalf. if they do it, awesome. but i personally dont want it due to all the s*** that can go wrong.

 

[MikeM.]

But this is just an educated opinion on my behalf. if they do it, awesome. but i personally dont want it due to all the s*** that can go wrong.

That's why I walk everywhere. There is simply too much to go wrong with a car powered by an internal combustion engine. Even the brakes which seem relatively simple and fool-proof rely upon multiple seals that could fail at any moment. (headshake

 

[V8toilet]

That's why I walk everywhere. There is simply too much to go wrong with a car powered by an internal combustion engine. Even the brakes which seem relatively simple and fool-proof rely upon multiple seals that could fail at any moment. (headshake

You contradict yourself Mike. You tout about how reliable your CX5 is (I agree it is), you tout about how you spend so much time driving your other motor vehicles like your motorcycles, and when you post pictures of your vehicles there's usually vast open land in the background that doesn't look like its a place were people would walk from place to place.

If someone else wrote this exact same statement wouldn't you write commentary trying to prove them wrong. Often you make very thoughtful valid points but I don't see it here.

 

[MikeM.]

You contradict yourself Mike. You tout about how reliable your CX5 is (I agree it is), you tout about how you spend so much time driving your other motor vehicles like your motorcycles, and when you post pictures of your vehicles there's usually vast open land in the background that doesn't look like its a place were people would walk from place to place.

You make some very good points there. So good, in fact, I would say your case is air-tight.

And that is why I thought my sarcasm would have been obvious to all. (dunno)

 

[V8toilet]

After reading your post again I do now see the sarcasm. Please except my apologies

 

[Unobtanium]

here is why i didnt take that question seriously. HCCI tech is far too costly to implement at a mainstream level. While making a statement saying its in the works, makes things sound good. it does not mean it's going to happen for a number of reasons.

Biggest issue is how hard it is to control an HCCI event. they are quite different than Diesels, although they say they are similar. only similarity is that it doesn't have spark ignition. Really thats where the similarity stops. Diesels work the way they due because the fuel injection can be actively timed by the injectors as fuel is injected into an already compressed air charge (top of the compression stroke almost. With HCCI the fuel and air enter the chamber at the same time, and ignite whenever the pressure and heat reach the proper point. Why is this an issue?

-Cold winters will make it SIGNIFICANTLY harder for the combustion to happen. sometimes not even happening at all. Hot summer days you will get early ignition. Weather temps effect HCCI greatly. Sure, heater and cooler assemblies could be implemented to help these issues, but that adds cost of another microcomputer along with other sensors and etc that are going to need to be added.

Valve actuation also effects HCCI greatly, along with quite a few other things. Also, HCCI due to the way it works operating on lean fuel mixtures, the peak temperatures are much lower than conventional gas and diesel engines. BUT, the low peak temperatures also lead to incomplete burning of fuel, especially near combustion chamber walls which leads to high carbon monoxide and hydrocarbon emissions.

Pre-ignition goes back to what i said about HCCI being hard to control when combustion happens. so pre-ignition will be harder to fight in an HCCI system. Also, although this seems to be where many Mazda is moving towards (doesn't mean i like it) HCCI engines have a small power range which is pretty much restricted to low loads by lean flammability limits and high loads by in-cylinder pressure restrictions

In short the overall complexity and issues fighting against the HCCI process, it will be quite tough to use HCCI engines in a mass produced cost effective way. As they are/will be far more expensive to build, engineer, and maintain than what we are currently using.

Also, Mazda is NOT the first people doing HCCI, GM had a running prototype back like 7-9 years ago i think it was. and there are other companies already attempting it. GM's version was a bit of a hybrid. but guess what, it only got 6 more MPG over the standard 2.2L Ecotec engine it replaced. Not worth the cost IMO. But this is just an educated opinion on my behalf. if they do it, awesome. but i personally dont want it due to all the s*** that can go wrong.

And yet people here will live with the 2.0L for the meager gains it has over the 2.5L.

 

[edj_03]

First, I must say, great thread...

I'm an extreme noob to Mazda... Bought into the Skyactive marketing hype this year matter of fact. Still, I can't argue (with myself, that is) that the CX-5 was the only vehicle in its class that hit the highest number of must haves/least number of compromises, I'd experienced during my research and tests drives.. Not to mention, it made me smile when driving [emoji7] ...3,000 miles later, it still does!

Regarding the Skyactive marketing. I immediately got the "...the sky's the limit..." mentioned in one of the videos above. Maybe a minority in this, based on all of the puzzled comments above. BTW, the active part I interpret should be apparent when you drive the vehicle. Something along the lines of keeping active, staying active, etc. Should appeal to the more mature family oriented driver that wants to keep some of the zoom, zoom while meeting their more practical tasks like driving multiple kids to their various activities, and all the gear associated. I certainly fit this demographic.

Besides, I'm rather a tech aficionado, when I can afford it. The CX-5 meets this need to a tee.

Regarding the HCCI, Yes, it may be a long shot. Still, I like many here I'm sure, are batting for Mazda to pull it off. Considering the ever tightening regulations for emissions and efficiency rules; if they cannot, we might all be driving a CR-V or some sort of electric vehicle when our CX-5 finally gives up the ghost. [emoji33]

 

[Unobtanium]

First, I must say, great thread...

I'm an extreme noob to Mazda... Bought into the Skyactive marketing hype this year matter of fact. Still, I can't argue (with myself, that is) that the CX-5 was the only vehicle in its class that hit the highest number of must haves/least number of compromises, I'd experienced during my research and tests drives.. Not to mention, it made me smile when driving [emoji7] ...3,000 miles later, it still does!

Regarding the Skyactive marketing. I immediately got the "...the sky's the limit..." mentioned in one of the videos above. Maybe a minority in this, based on all of the puzzled comments above. BTW, the active part I interpret should be apparent when you drive the vehicle. Something along the lines of keeping active, staying active, etc. Should appeal to the more mature family oriented driver that wants to keep some of the zoom, zoom while meeting their more practical tasks like driving multiple kids to their various activities, and all the gear associated. I certainly fit this demographic.

Besides, I'm rather a tech aficionado, when I can afford it. The CX-5 meets this need to a tee.

Regarding the HCCI, Yes, it may be a long shot. Still, I like many here I'm sure, are batting for Mazda to pull it off. Considering the ever tightening regulations for emissions and efficiency rules; if they cannot, we might all be driving a CR-V or some sort of electric vehicle when our CX-5 finally gives up the ghost. [emoji33]

HoMoCo hasn't made anything worth driving since they killed the NSX and S2000.

 

[V8toilet]

First, I must say, great thread...

I'm an extreme noob to Mazda... Bought into the Skyactive marketing hype this year matter of fact. Still, I can't argue (with myself, that is) that the CX-5 was the only vehicle in its class that hit the highest number of must haves/least number of compromises, I'd experienced during my research and tests drives.. Not to mention, it made me smile when driving [emoji7] ...3,000 miles later, it still does!

Regarding the Skyactive marketing. I immediately got the "...the sky's the limit..." mentioned in one of the videos above. Maybe a minority in this, based on all of the puzzled comments above. BTW, the active part I interpret should be apparent when you drive the vehicle. Something along the lines of keeping active, staying active, etc. Should appeal to the more mature family oriented driver that wants to keep some of the zoom, zoom while meeting their more practical tasks like driving multiple kids to their various activities, and all the gear associated. I certainly fit this demographic.

Besides, I'm rather a tech aficionado, when I can afford it. The CX-5 meets this need to a tee.

Regarding the HCCI, Yes, it may be a long shot. Still, I like many here I'm sure, are batting for Mazda to pull it off. Considering the ever tightening regulations for emissions and efficiency rules; if they cannot, we might all be driving a CR-V or some sort of electric vehicle when our CX-5 finally gives up the ghost. [emoji33]

Yes, I agree with you completely. Your explanation for Skyactiv is very concise. I too value great engineering and I have a background in automotive just because I've found it to be so interesting when I was younger. I was once an ASE Master certified technician and even though I've given that up many years ago I still love to be involved in it in some way when the opportunity presents itself. Like you I find Mazda's simple approach to improving old school technology to an advanced state very interesting and like you and most here I like driving this vehicle even though its an SUV (SUV's in general are not fun to drive but this one).
(drive2)

 

[Unobtanium]

Yes, I agree with you completely. Your explanation for Skyactiv is very concise. I too value great engineering and I have a background in automotive just because I've found it to be so interesting when I was younger. I was once an ASE Master certified technician and even though I've given that up many years ago I still love to be involved in it in some way when the opportunity presents itself. Like you I find Mazda's simple approach to improving old school technology to an advanced state very interesting and like you and most here I like driving this vehicle even though its an SUV (SUV's in general are not fun to drive but this one).
(drive2)

I agree. I will admit though, I am still torn on the "fun ride" I'm going to get in 3-5 years. SRT JEEP, Viper, C7, Exige/Elise are all being considered. I don't want to buy new again, so I'm not worried about what will come out between now and then, as I want to buy something that's pre-owned, in a model that's been out for a few years so that we can see what gremlins it has. Not an early adopter.