SkyActiv X: It’s complicated …. and yet, so simple

Opportunity at last to try the world’s first compression ignition petrol engine.

MORE power, using less fuel; simulates a diesel but with petrol as the fuel, sounds nicely growly in the CX-30 yet is almost eerily quiet in the other current recipient, the Mazda3. 

If you need to explain the 2.0-litre SkyActiv-X engine and its Spark Controlled Compression Ignition set up at layman level, then that might be about as easy as it gets.

If more information is sought, you might like to mention that it gives best thrift opportunity in urban operation, lends most impressive thrust when pushing on quite a bit, though that’s not necessarily because it’s supercharged, because that ingredient is not used in orthodox manner.

Likewise, even though it has a hybrid component – the first Mazda here with this – it cannot really be categorised as being like, say, a Toyota Prius. 

If this is starting to sound a bit complicated, then wait until you go through the finer points of this engine’s design. 

As much as we’ve laid the groundwork with what this is all about, not least with the excellent backgrounder by Colin Smith some weeks ago (https://www.motoringnz.com/news/2020/8/24/the-science-of-spcci-explained), a succinct explanation based on what he gleaned from having driven the car in a pre-release format in Germany last year, the impact of direct experience is nonetheless little short of profound.

On technical grounds, it presents as such a mean feat of engineering as to be a ‘wow’, not just of the now, but perhaps for years to come.

The potential surely has to be huge and it’s a dead cert we’ll see more Mazda passenger models being crossed off for adoption of the X – which, if you hadn’t already twigged, is representative of the crossover from spark ignition to compression ignition.

Full explanation of why it is important, what it delivers and how it breaks the mould is not a matter of a one-sentence summary. The challenge for salespeople is obvious, all the moreso because its provision delivers with enough of a premium to deliver push the recipient Mazda3 hatch and CX-30 compact crossover into a new territory for both.

The first siting at $51,995 and the second at $54,990 means these platform-sharers respectively fly $3200 and $4000 above the Limited editions that have, until now, been the flagships of each line. 

The cost loadings are not purely for this drivetrain but also reflect the cars being in an extra-lavish Takami spec that has not offered with either previously, but has featured in other models.

This brings additional luxuries - the Mazda3 gains a gloss black finish alloy wheel, 360-degree camera and a heated steering wheel whereas the CX-30 adopts high gloss 18-inch alloy wheels, 360-degree camera and a powered tailgate - though debatedly there’s nothing that shouts out as a ‘must-have.’

Also influencing the bottom line is that the engine here is in an ‘M Hybrid’ format, which introduces involvement with an integrated, belt-driven starter generator and 24-volt lithium-ion battery which assists the engine and recoups lost energy during deceleration. 

The addition isn’t akin to the best-known hybrid system, from Toyota: The market leader’s has a bigger (and heavier) battery and more powerful electric motor. Yet M-Hybrid is hybrid enough to qualifies the SkyActiv’s to be considered as being petrol-electric and therefore as an interim toward Mazda’s first electric car, next year’s MX-30.

As we’ve said before, SPCCI’s potential to deliver will be eagerly monitored. For one, everyone will be keen to establish the value aspect; a focus that becomes important because of the premium over the ‘regular’ four cylinders that provision in these models in 2.0-litre and 2.5-litre formats.

Is it worth it? Quite literally, you’re talking bang for buck. A first taste suggests the on-paper expectations and on-road outcomes are going to take some consideration. 

Mazda claims a 12 percent increase in torque around 1000rpm lower down in the rev range than evidences in the orthodox petrols also availing in the recipient cars, 10 percent lower CO2 emissions and a 10 percent improvement in overall fuel economy, including a 15-17 percent urban test improvement. 

It also cites an optimal combined fuel economy rating of 5.5l/100km for the Mazda3 (and 6.0L/100km for the CX-30), both with the six-speed automatic that comes here. 

The manual Mazda3 not coming here is the true champion. It claims 4.3 litres per 100km is close to Toyota Prius levels of efficiency, though that’s with the NEDC testing regime, a format that has now been largely shelved. Using the now preferred 'real world' (WLTP) fuel economy formula, the claimed consumption rises 1.1L/100km. FYI, the 2.5’s optimal drinking rate is 6.6L/100km. 

So there’s that. The cited outputs of 132kW/224Nm also place it between the existing 2.0-litre and 2.5-litres, which respectively make 114kW/200Nm and 139kW/252Nm. 

Even so, the performance from the new unit is tangibly different. Pre-drive talk about how much more ‘natural’ this engine’s response is, particularly in accelerative feel, how smooth it is on launch and when downshifted, how it delivers a special sound signature seemed awfully bold. Could it really make that much impact?

Actually, yes. From first impression gathered over three hours’ running in several cars, there’s a lot to seem highly promising. It feels stronger over a broader rev band (like a diesel), revs more enthusiastically to a higher redline (like a regular petrol), pulls more strongly (like a six cylinder) and has, in the CX-30, an intriguingly gruff note, almost like a five-cylinder unit.

There’s not an absolute perfection, in that the cars I drove all expressed a slight hesitancy in initial step-off that might be as result of these being all but brand-new (they’d just landed the week prior) or it could transpire to be a signature. Just like a diesel? Well, actually, very much so.

That also seems to be the one occasion where it feels tangibly difference to the regular engines. Even though the car runs in SPCCI mode most of the time, you’d be excused for not realising. The changeover from one mode to another is hard to detect. Hence, I guess, why there’s a specific display on the infotainment screen to identify what’s happening and when. Under spark ignition, the pistons in the infographic change to red. It didn’t seem to happen too often on my drive but I wasn’t looking too often, due to weather conditions on the day.

Our foray from Auckland deep into the Waikato synched with a massive storm rain of such lashing fury that the radar and camera guided safety and support systems in a CX-30 I was running in occasionally became so overwhelmed they warned of temporary shut down and it became prudent to slow to a crawl as the road became more like a river. 

This, and other factors that need not be explored here, kinda ruined the idea I’d had of trying to get a handle on the engine’s efficiency through comparing with the outcomes I’d seen in a 2.5 Limited CX-30 I’d transferred from. Anyway, it really became such a battle of survival for a while that any deep thought about economy outcome will have to await a comprehensive test.

On the efficiency side, though, SkyActiv-X stands as a big element of the make’s corporate goal to reduce ‘well-to-wheel’ emissions by 50 percent from 2010 to 2030.  In places where low C02 counts, the engine in the form as we see it is heading down the right road with claimed emissions of 127 grams per kilometre.

In respect to this, those of serious engineering bent will identify that Mazda has taken quite a remarkable route to achieve results that could conceivably also been reached by other means; fitting a smaller turbo engine under the bonnet or creating a petrol-electric hybrid.

Mazda freely admits the route it has forged was certainly a challenge and a half. A Homogeneous Charge Compression Ignition (HCCI) engine that simulates how diesels operate but with petrol, with compression rather than spark igniting a lean fuel-air mixture, took a lot of figuring. And time. And money. Mazda was not the first to try but is, to date, the only brand to have stayed the course. 

Even though it uses a spark plug, unlike the diesel design that inspired it, SkyActiv-X is genuinely a compression ignition approach. The crux of the spark plug is that it can be relied upon in high-load situations but also to bring the lean air-fuel mixture to the point of instantaneous homogeneous combustion – the point where all the mixture combusts instantly at the one moment. By contrast, in a normal petrol engine, the spark plug initiates combustion in the piston chamber that moves away from spark plug and is less efficient.

If that’s befuddling, think of it as a colleague much smarter than I has put it. A normal combustion process is like a strip of matches lined up in row – one ignites and then quickly the other match heads ignite away from the initial spot of combustion. Compression ignition is like all the match heads in the row igniting at the same time. It results in a much faster combustion time.

Lift the bonnet and the X engine appears to fill out more of the engine bay than a regular unit. That’s really because of the supercharger, whose role is far from orthodox is this application, in that it’s here to push the massive volumes into the engine that are requisite to its operation. As explained in the previously published backgrounders.

With the electric age coming up fast, why bother with a different kind of petrol engine? Simply because, as much as it also intends to commit to battery-pure driving, Mazda also believe fossil fuels will continue to be part of our driving life for decades to come yet. However, it also believes we need to do more with what’s left.

It’s an interesting thought that the make that takes this attitude now was also steadfastly committed to another radical engine, one without the stop-start, up-down reciprocating motion of pistons and connecting rods.

Is there irony that the brand that stood so ardently behind the Wankel rotary, surely the simplest engine design ever, is now banking on another that stands out for a high degree of complexity? Well, perhaps, but you have to admire any company with the pluck to think outside the square. In this respect Mazda, one of Japan’s smaller makers, is a true giant.

Consumer uptake will decide the merits. Mazda NZ anticipates the SkyActiv-X editions will achieve around 15 percent of take-up within their respective model lines. The only ask of owners is that they feed it 95 octane or higher petrol (whether it accepts ethanol blend fuel is being looked into) and that’s all. Servicing-wise, it demands no special requirement.

Mazda here doesn’t know what other candidates are in line for SkyActiv-X, but it will not be surprised if Hiroshima widens the availability of this tech and continually refines it, the next obvious step being to perhaps go from a mechanically-driven supercharger to one running on electricity.

2017 Mazda CX-5: Class leader raises the bar

The first-gen CX-5 departs with rock star status. No need for tears – a replacement with an all-new body and interior, and more cargo space, refinement and technology seems set to also top the charts.

PARKING the latest CX-5 alongside its outgoing predecessor is an interesting experience – they’re different, just not as different as you might think.

I suspect that strong sense of familiarity will hang over the driving experience. As well it should. After all, the engines, six-speed automatic gearbox and around half of its componentry are carried forward.

This isn’t so much Mazda being reluctant to change; more a case of not wanting to hex a good thing.

Mazda is on a roll, but CX-5 has been especially good for the Hiroshima outfit. Locally as internationally, the first gen launched with a roar in 2012 and promptly set out to beat all in-house volume predictions.

Here it swiftly bumped Mazda6 from local market dominance and ithin three months of coming on sale was attracting an order count far above the forecast 160 units per month. It departs as Mazda NZ’s monthly best seller 39 on occasions and as the country’s favourite mid-sized SUV (when rental counts are excluded, otherwise it’s the Toyota RAV4).

It’s been just as hot internationally, something programme manager Masaya Kodama admits took HQ by surprise. No-one then anticipated SUVs being the next big thing, but in hindsight the timing was perfect. Analysis suggesting a 150,000-unit annual global build run was quickly proved laughable. Of the 1.5 million vehicles Mazda made in 2016, around 370,000 were CX-5s – coincidentally, the firm also knocked out 1.5 million CX-5s during its production span.

And gone so soon? Most product cycles run seven years, but for Mazda it’s five, hence why there’s a now new one. Kodama and his 500-strong team had a relatively straightforward remit: Build on the previous car’s many strengths polish out its relatively few shortcomings and, above all else, keep to the overall winning recipe. No pressure then.

Priority requirements were to bring styling up to speed and achieve better refinement, safety and comfort. Mission accomplished? Two days driving the mid-level GSX and top Limited suggest Mazda has another winner on its hands.

All the same, don’t expect revolution.

Fact is, while the gen two car delivers an all-new body – taking clear cues from the larger CX-9 - and interior, and more cargo space, refinement and technology, it is not all new.

The four-cylinder powertrains are largely unchanged - effort has been aimed at making the 2.5-litre petrol unit quieter and the 2.2-litre turbo-diesel smoother and official fuel consumption increases by up to half a litre per 100km (although Mazda claims all models are more efficient in the real world) – but, overall, operational aspects are unaltered, as are outputs.

The six-speed automatic is also only modestly refined, with minor ratio changes being the main alteration. Save for tune, suspension and electric steering are unchanged. A lot of other components are simply carried over.

Don’t be disappointed. Fact is, there was no need for a clean sheet. It already hit the sweet spot in terms of size, price, economy, performance, dynamics and technology. This new generation largely nails the few criticisms that the outgoing one had to carry; chiefly a lack of refinement in terms of engine, road and wind noise.

The ‘ain’t broke, don’t fix’ approach reflects in it being around the same size as the outgoing car, still provisioning in GLX, GSX and Limited specifications and why the pricing represents an average increase of just $700, meaning it now sites from $39,995 to $57,495.

Keeping the drivetrain potentially isn’t just prudence and cost-saving. With those engines, a pair of petrols - a 2.0-litre for the GLX, 2.5 for the higher grades, the first front-drive only, latter powering in front or four-wheel-drive – and a 2.2 diesel that only runs in all-wheel-drive format, it might simply be all a matter of timing.

Kodama won’t say how much longer they’ll remain in service, but suggests second generation SkyActiv powertrains will be in commission next year. Also, of course, there’s clearly good chance the stonking 2.5-litre turbo petrol that performs so brilliantly in the CX-9 has to be a starter, sooner or later.

The addition of more safety and convenience equipment and more sound insulation, and the car also being slightly longer and stiffer means it is also heavier - on average kerb weight has increased by around 40kg. How the 2.0-litre feels about this remains unknown; none were on the launch. But the 2.5 and 2.2 don’t seem to sweat it.

Mazda is resistant to fully autonomous cars, suggesting ‘hands-off’ jars with its intent to keep an ingredient of driver fun, but it has stepped up the suite of active safety technology – dubbed i-Activsense – that is classed as ‘level one’ autonomy. 

All variants get a rear-view camera, rear sensors and autonomous emergency braking, which is now capable of also detecting pedestrians (between 10-60kmh) as well as vehicles (4-80kmh).

The Limited has Mazda radar cruise control with full stop and go functionality, traffic sign recognition, lane departure and lane-keep assistance systems as well as side camera and smart brake support. What Mazda needs to do, now, is upgrade our road markings; on our drive, the lane-keep struggled and occasionally gave up entirely.

The cabin now feels far more premium than its predecessor. The tablet style 7.0-inch infotainment screen is more logically located and it and the switchgear could have been lifted from an elite Euro; so too some of the soft touch surfaces that are a big improvement over the outgoing car’s hard black plastics. Finish of all cabin surfaces is exceptionally good, in fact. 

The one big disappointment for me is that it still lacks Apple CarPlay and Android Auto. Kodama says the challenge of integrating these functions into Mazda’s bespoke MZD Connect infotainment suite continues to challenge the company’s software engineers. But they’ve almost cracked it, he assures. “We will have it.”

That’s good news, because it is a car in which good sounds can easily be heard through bad ones – that’s road, engine and wind noise – having been largely expunged; the diesel in particular is extraordinarily refined. There is more sound deadening everywhere, including acoustic glass in the front-side windows (another CX-9 trick) and more door (and door handling) sealing to eliminate as much wind noise as possible.

Yes, there's still some tyre roar, most notably from those Limited-level 19-inch wheels, which deliver a firm ride on broken seal and mid-corner lumps, but it has to be said that the diesel flagship nonetheless remained so quiet at all roads speeds that it has potentially reset the class benchmark.

Speaking of .. chassis dynamics have always been a CX-5 highlight and rest assured it hasn’t lost the sporty edge that emphasises the sincere if quirky Mazda ‘horse and rider’ credo.

That all versions come with G-Vectoring Control (GVC), which that delivers unified control over steering and chassis systems by finely controlling engine torque based on steering and acceleration inputs, isn’t an effort to disguise any dynamic flaws.

Also now standard to the CX-3, GVC is hard not to like. It evidences more coherently in the CX-5 than the Mazda3, perhaps because of the extra weight but also the higher centre of gravity. It’s impressive how the car, when pushed hard through a bend, seems to find ability to pull itself into an apex, rather than wash out.

This car doesn’t just rely on electronic means to handle well. There is a load of grip at all times and it has a nice balanced feel.

Petrol engines are picking the sales pace in this category but, in this car, I’d still go for the diesel; it’s such a fantastically smooth and muscular performer, with almost petrol-like pick up but less vocal even when pushed. And it works extremely well with an automatic that, despite showing its age on paper, remains hard to fault. To me, a diesel Limited in the new hero colour, Soul Red Crystal, is the perfect CX-5.

Mazda NZ reckons this year it will sell more than 3000 – a first for any car it has sold here. I’d say it’ll be a cinch for a car that, despite not being a rebirth, nonetheless feels completely reborn.