14:1 is the magic number!

Matt Simis

Tea 1000 wrote: »

Maybe you're right, but at least we have camps! You stay out there in your "nothing"!

Pff, dont put me in either camp. Im not oohing and ahhing over this as Im some sort of pro-Audi/BMW zealot. Im simply applying my understanding of diesel engines and the simple truth that high compression = high efficiency. The lowest compression you will find for a diesel is just about 14:1. This isnt some new Mazda advancement, its just crap. Old crap.

A 14:1 compression on a petrol is very high, thats all well and good. But this thread is based on some Journos perhaps limited understanding of CR and factory floor tooling.. which little consideration for the end product.

Im a driver, I like cars and technology. This is a thread about Mazda saving money on tooling by making a strung Petrol engine (which may be quite good, but likely also quite particular about fuel quality) and a low efficiency diesel engine from the same core block.

As a driver thats pretty dull "news", verging on simply "ugly" design. As a bean counter, Im sure this is wonderful news. It has nothing however to do with what the "Germans" do.

Matt Simis

The lack of info and random statements got me searching and I found this much better article about the two new Mazda engines (SkyActiv-G and SkyActiv-D):
http://www.autoguide.com/manufacturer/mazda/mazda-skyactiv-prototype-review-video-1587.html

The Petrol Engine

To achieve maximum power the engine gets a 14:1 compression ratio, the highest of any gasoline powerplant on the market – although North American versions will make use of a 13:1 compression ratio allowing them to run on regular 87 octane fuel. Normally such a high compression ratio would result in knocking, but Mazda has solved this though..

The Diesel Engine - lowest compression diesel on market (Edit thats not really true though is it?)
Designed for high RPM, high torque in the higher part of the RPM band

The 14:1 compression ratio makes for significantly reduced temperatures inside the combustion chamber, allowing for an earlier injection of fuel through more efficient piezo injectors. This longer period of mixture with the air makes for a more thorough combustion with fewer emissions. This system is then combined with a two-stage turbo to maximize power and variable valve lift on the exhaust valves to help prevent misfiring. Plus, yet another benefit is that the reduced compression allows for the use of lighter components, shedding 10 percent from the block, crank and con rods.

Despite all these improvements it still sounds like a tractor, something that certainly isn’t going to help popularize an engine technology that already has a negative view by the buying public.

The article suggests the "power and economy" (no quotes of economy and power is well below a 520d..) is the result of the low compression (in the diesel, they of course state the opposite on the petrol).. flying in the face of 90years of diesel engine design. IMO, I think its simply a newer diesel and gets a 20% increase over Mazda's current 2.2 (no real MPG figures in article).. but those improvements are not "because its a low compression engine", they are because its a new diesel block with better injectors, tuning and a twin scroll turbo. The low Compression is a necessity (IMO) of their limited production ability.


I dont gush about 520d's but they seem to be a much better engine in most regards and out for years now. It has lower peak torque than the Mazda, but is also 10% smaller (2.0 vs 2.2 in the Mazda). The BHP on the BMW 2.0 is about 10% higher than the Mazda 2.2.

Tea 1000

Matt Simis wrote: »

The lack of info and random statements got me searching and I found this much better article about the two new Mazda engines (SkyActiv-G and SkyActiv-D):
http://www.autoguide.com/manufacturer/mazda/mazda-skyactiv-prototype-review-video-1587.html

The Petrol Engine


The Diesel Engine - lowest compression diesel on market (Edit thats not really true though is it?)
Designed for high RPM, high torque in the higher part of the RPM band



The article suggests the "power and economy" (no quotes of economy and power is well below a 520d..) is the result of the low compression (in the diesel, they of course state the opposite on the petrol).. flying in the face of 90years of diesel engine design. IMO, I think its simply a newer diesel and gets a 20% increase over Mazda's current 2.2 (no real MPG figures in article).. but those improvements are not "because its a low compression engine", they are because its a new diesel block with better injectors, tuning and a twin scroll turbo. The low Compression is a necessity (IMO) of their limited production ability.


I dont gush about 520d's but they seem to be a much better engine in most regards and out for years now. It has lower peak torque than the Mazda, but is also 10% smaller (2.0 vs 2.2 in the Mazda). The BHP on the BMW 2.0 is about 10% higher than the Mazda 2.2.

But surely lighter components in a diesel engine would help it rev more freely, and higher torque at higher RPM are both qualitys which are exactly what a diesel needs? As another car enthusiast and driving enthusiast, those two are things I look for in a diesel ahead of fuel economy (provided the economy isn't drastically reduced).
And a high compression petrol with higher torque in the low to mid range is also something that a petrol would benefit from?
You can accuse them about being bean counters, but at the end of the day it's all about how you go about saving your beans that counts.
For all the chassis sharing that the VAG group do, their cars are dull to drive. I'd have more faith that Mazda can make these engines work well than VAG can make their cars properly entertaining.
Mazda's already have excellent chassis for their respective classes.

My point is while you say things like real enthusiasts look down their noses at any attempts to save money, I say fair play to them for trying to save money in a unique new way that may actually have benefits on the end product.
Besides, this is a forum supposedly for car enthusiasts. 1 thread every year seems interesting, the rest is the usual drivel about what Fiesta will fit in what Octavia's boot, or the answer to all unasked questions is a Mondeo, or someone's foglight thread lasted 8 minutes. Hence I figured this might qualify as something interesting!

Joe 90

Matt Simis wrote: »

I think thats an optimistic way of looking at it. The way I see it they have stretched and fudged 2 "opposed" engines and made one core block to save on production. Its the move VW or BMW would not make as clearly a 14:1 Compression ratio in a Diesel is kinda crap and in a petrol will put huge strain in ignition systems and preclude low quality (sub 95octane anyhow) fuel entirely.

Its a great example of cutting corners.

I think that Japland has 100 octane available so I wonder if we will ever see these 14:1 engines in Euroland or the US of A? Be very nice if we did.

SouperComputer

Joe 90 wrote: »

I think that Japland has 100 octane available so I wonder if we will ever see these 14:1 engines in Euroland or the US of A? Be very nice if we did.

Maybe they'll run a different cam profile and or ignition map to compensate a little for the euro motors.

I'd be interested to see the dyno curve on this twin turbo 14:1 diesel. Notsomuch for the peak, but to see how the curve compares to other diesels. Done right, it should offer a broader range than current offerings with heavier internals and more parasitic loss with higher "mechanical" CR's. Mazda are no stranger to variable intake lengths as well as sequential turbos. Put all this together and you have a very nice diesel package that offers a broad powerband.

Matt Simis

Tea 1000 wrote: »

But surely lighter components in a diesel engine would help it rev more freely, and higher torque at higher RPM are both qualitys which are exactly what a diesel needs? As another car enthusiast and driving enthusiast, those two are things I look for in a diesel ahead of fuel economy (provided the economy isn't drastically reduced).

Thats what Mazda PR says. The reality is this new lightweight Diesel has the same RPM limit (if not lower), lower BHP and lower torque than a 10year old but remapped Alfa 2.4JTD (yes its remapped, but its 2009 multijet version is even better, pick either and they look excellent by comparison). The hype and promise of a lightweight construction high RPM, high economy and high power Diesel block is just not here in reality, no matter how nicely its packaged!

Tea 1000 wrote: »

And a high compression petrol with higher torque in the low to mid range is also something that a petrol would benefit from?You can accuse them about being bean counters, but at the end of the day it's all about how you go about saving your beans that counts.

Yep, 14:1 on a petrol while tricky to pull off (knock problems) would be great, no one is questioning that.
Agreed on how you save money.. I think this is a great example of a bad way of saving money. The results and alleged performance of this "reinvented" diesel engine look fairly mild and weak.

Tea 1000 wrote: »

For all the chassis sharing that the VAG group do, their cars are dull to drive. I'd have more faith that Mazda can make these engines work well than VAG can make their cars properly entertaining.
Mazda's already have excellent chassis for their respective classes.

VAG chassis's are fairly dull.. but thats absolutely nothing to do with this thread. The Mazda's I have experienced first hand did not impress me, but thats not say I think every Mazda is bad.

Tea 1000 wrote: »

My point is while you say things like real enthusiasts look down their noses at any attempts to save money, I say fair play to them for trying to save money in a unique new way that may actually have benefits on the end product.

I say A for effort, C for result.

Tea 1000 wrote: »

Besides, this is a forum supposedly for car enthusiasts. 1 thread every year seems interesting, the rest is the usual drivel about what Fiesta will fit in what Octavia's boot, or the answer to all unasked questions is a Mondeo, or someone's foglight thread lasted 8 minutes. Hence I figured this might qualify as something interesting!

This is a very interesting thread! Just cos Im not agreeing that Mazda have done something great here doesnt make it a "bad" topic. I didnt know about this engine block sharing idea of theirs before this. Kudos for the topic!

SouperComputer wrote: »

I'd be interested to see the dyno curve on this twin turbo 14:1 diesel. Notsomuch for the peak, but to see how the curve compares to other diesels. Done right, it should offer a broader range than current offerings with heavier internals and more parasitic loss with higher "mechanical" CR's. Mazda are no stranger to variable intake lengths as well as sequential turbos. Put all this together and you have a very nice diesel package that offers a broad powerband.

Its not a multiple turbo though (ala 535d) its a twinscroll (single) turbo isnt it?

Matt Simis

LIGHTNING wrote: »

To be fair Matt even the basic range of Mazda`s drive quite well. Well above the bore fest that you get from most of VAG range.

Lol, why are we talking about/comparing VAG cars at all (which I agreed on, mostly numb) at all? Even the basic range drive well? I wouldnt know, I wouldnt drive a basic model of anything, Im just that cool. :cool: I dont care for the majority of BMWs or Audis or German cars or whatever, Im not some fanboy. Most products from most companies are $hit because people want $hit, I dont advocate marques.

This thread is about Mazda "reinventing" diesels and introducing a 14:1 CR engine as a first (when it clearly isnt, see link) and somehow "much better" than the latest engines from their competitors (be it VAG, BMW or Alfa) when in regards power, BHP and economy, it isnt. Its good, its quite competitive, but the gushing about it in the thread and articles (ie the Mazda PR regurgitated articles) is way OTT. If people would take the time to read up on the engine, the concept and how it compares, they would realise this too. Its only logic.

All this "sure Mazda are great lads for trying", come on guys, we want results, not marketing spin and back patting.

Tea 1000

Matt Simis wrote: »

Lol, why are we talking about/comparing VAG cars at all (which I agreed on, mostly numb) at all? Even the basic range drive well? I wouldnt know, I wouldnt drive a basic model of anything, Im just that cool. :cool: I dont care for the majority of BMWs or Audis or German cars or whatever, Im not some fanboy. Most products from most companies are $hit because people want $hit, I dont advocate marques.

This thread is about Mazda "reinventing" diesels and introducing a 14:1 CR engine as a first (when it clearly isnt, see link) and somehow "much better" than the latest engines from their competitors (be it VAG, BMW or Alfa) when in regards power, BHP and economy, it isnt. Its good, its quite competitive, but the gushing about it in the thread and articles (ie the Mazda PR regurgitated articles) is way OTT. If people would take the time to read up on the engine, the concept and how it compares, they would realise this too. Its only logic.

All this "sure Mazda are great lads for trying", come on guys, we want results, not marketing spin and back patting.

People don't want sh!t. Audi didn't make an S8 for the likes of you. Nor did BMW make the 850CSI for you. You buy used, when they're almost worthless in monitary terms but fantastic value. You're wise to do so, but BMW and Audi don't care about the likes of you. They build those machines for people who will spend a massive amount of money on them.
To my mind, that's how cars like that should be judged too. You can't look at an S8 and compare it to a Mazda of any sort, Mazda don't have a competitor to it. Even if they did, it wouldn't sell thanks to badge snobbery among the very people who can afford those cars.
I credit Mazda because they make an effort to make all the cars they have in each category as entertaining relative to the competition as they can. To a large degree, they succeed.
I'm not here to say Mazda now have the best diesel in the world, only that they have a pioneering engineering method for their engines that it looks like at this point is working quite well. Not perfectly well, as you point out, but quite well in a first effort is quite good! Not many companies can manage that.

Matt Simis

For the love of god why do people think that every poster on a car forum is talking about their car when stating something disparaging about another car. Im not comparing a V8 S8 or V12 BMW to a diesel Mazda3 or some other nonsense. Give me some credit man!

People do want to buy low end $hit (my definition), how could you possibly think otherwise? The vast majority of the car buying public want something mundane, bland and reliable. See the Nissan Tida, the Carina the Polo, the Golf, the Mondeo, the 318i etc etc. These cars are all crap to an enthusiast (think outside the box as if we were not Irish with our warped VW, FWD 1.4litre obsession).

I'm not here to say Mazda now have the best diesel in the world, only that they have a pioneering engineering method for their engines that it looks like at this point is working quite well. Not perfectly well, as you point out, but quite well in a first effort is quite good! Not many companies can manage that.

This is not their first effort by a long shot! It looks quite good, its reasonably competitive, but to branch away from the norm and take such risks with design (thinner, weaker blocks!) I would be personally demanding a greater return on that investment (in MPG, power or something).

Tea 1000

Matt Simis wrote: »

For the love of god why do people think that every poster on a car forum is talking about their car when stating something disparaging about another car. Im not comparing a V8 S8 or V12 BMW to a diesel Mazda3 or some other nonsense. Give me some credit man!

People do want to buy low end $hit (my definition), how could you possibly think otherwise? The vast majority of the car buying public want something mundane, bland and reliable. See the Nissan Tida, the Carina the Polo, the Golf, the Mondeo, the 318i etc etc. These cars are all crap to an enthusiast (think outside the box as if we were not Irish with our warped VW, FWD 1.4litre obsession).

I think that many people can only afford to buy low end sh!t and don't actually want the sh!t to be all that sh!tty. Hence Mazda give people some excitement to fit their budget. I'm just saying that it's not fair to categorise anything aimed at being affordable as sh!t.

Matt Simis wrote: »

This is not their first effort by a long shot! It looks quite good, its reasonably competitive, but to branch away from the norm and take such risks with design (thinner, weaker blocks!) I would be personally demanding a greater return on that investment (in MPG, power or something).

Fair point. I guess time will tell. Unfortunately we're in a time when companies need to be innovative in their methods of serious cost cutting just to stay afloat. Saab are as good as gone, many other companies are in serious debt, I'd like as much competition to stay in the market as possible. THat's what gets us the best products!

Matt Simis

Tea 1000 wrote: »

I think that many people can only afford to buy low end sh!t and don't actually want the sh!t to be all that sh!tty. Hence Mazda give people some excitement to fit their budget. I'm just saying that it's not fair to categorise anything aimed at being affordable as sh!t.

Fair point. I guess time will tell. Unfortunately we're in a time when companies need to be innovative in their methods of serious cost cutting just to stay afloat. Saab are as good as gone, many other companies are in serious debt, I'd like as much competition to stay in the market as possible. THat's what gets us the best products!

TBH, this is a fair assessment of the market too. No point in making expensive awesome things that you rightly point out I personally wouldnt pay for till a decade later and going out of business in the meantime!

Fishtits

I'm still sceptical.

Mazda have pulled this "world first" stunt before yet have never lead the pack so to speak.

Dress it up in all the fancy names you like but it has to adhere to the laws of physics at the end of the day.

The Japs are not big diesel innovators, its not their global market, for a niche player like Mazda to come up with the next best thing is a push too far for me I'm afraid.

Time will tell.