Mazda's SKYACTIV Technology: The Comprehensible Bits

Brendan McAleer
by Brendan McAleer
mazda s skyactiv technology the comprehensible bits

I am sitting in a parking garage in a throng of torpid auto-journalists, nearly all of whom are wearing the same glazed expression of terminal information overload. On-screen, molecules of fuel and air are doing a complicated little computer-animated dance, as narrated by Susumi Niinai, program manager at Mazda’s powertrain development division. His English, while Japanese-accented, is better than, y’know, mine, but the concepts he’s explaining approach the limit of comprehensibility to the lay-person. Mind you, it’s a pretty nice parking garage.

Some of you, like me, may have been hearing all the rumblings about Mazda’s new SKYACTIV technologies and been wondering whether it’s going to turn out to be a series of technological breakthroughs or, alternatively, a load of complete cobblers thought up by some Zoom-Zoom marketing guru.

Good news everyone! It’s the former. Bad news everyone! I have to try to explain it to you. And I borderline don’t understand it myself. Here goes…

First, let’s set aside Niinai-san’s well-illustrated presentation on the SKYACTIV engine series for a moment, and talk in generalities. As was repeatedly hammered into our heads throughout the day, Mazda is a small company with limited resources.

What’s more, they’re a small company in trouble. How much trouble? Well, previous posts have outlined current flagging sales and enough profit drops to alarm Mazda fans. This is not good. To be frank, if Saab goes the way of the 9-2x Dodo a few orthodontists may be mildly upset, but for the rest of us it’s a big ol, “Meh.” Mazda on the ropes though? For the enthusiast driver, that’s bad.

So how does a beleaguered company without the resources of a Toyota or Nissan take on the pressures of ever-increasing efficiency standards? More than that, how do you pull off competitive MPGs while still maintaining the apparently-conflicting mandate of maximizing driver involvement as a priority? Two choices: cut corners, or clip the apex.

Make no mistake, Mazda isn’t interested in broadening appeal by blurring their focus. I heard the concept of jinba-ittai repeated so many times during the various presentations I was on the point of climbing on a horse and shooting someone in the face with an arrow.

Additionally, partnerships don’t seem to be high on the priority list. While there is some sort of upcoming agreement with Toyota on the hybrid powertrain front, Mazda seems to have little enthusiasm for a percentage ownership by a larger company that might allow for an increased R&D budget. When asked if anything similar to the previous Ford arrangement might be sought going forward, Mazda’s gurus said something to the effect of, “the future is unpredictable, but we don’t expect so.” They were scrupulously polite, but one might as well been asking them if they were hoping a disfiguring skin disease might re-appear.

Without the bankroll, Mazda’s got to box clever. It’s all very well to identify brand values, and quite frankly, it’s heartening to hear a group of enthusiastic engineers reaffirm that the Japanese Lotus still puts “fun-to-drive” at the top of their to-do list, but how do to so on a shoestring? First, streamline.

“Monotsukuri Innovation” is Mazda’s way of bundling architecture together to reduce costs. The cutaway SKYACTIV platform on display clearly showed a transmission tunnel capable of supporting an AWD variant, but the chassis was intended for next-gen Mazda3 and Mazda6 cars. With minimal changes needed to build the CX-7 and upcoming CX-5 off the same platform, weight-savings and rigidity developments should echo throughout the entire Mazda range.

Much hay has been made of Mazda’s borderline-impossible weight target for the next MX-5. With a total weight reduction of just 100kg, the SKYACTIV body and chassis don’t seem as revolutionary – until you notice that no exotic materials are involved: the savings are realized purely though better design and a moderate (20%) increase in the use of high-tensile steel.

By removing curves and kinks from the underbody, Mazda’s prototypes boast increased safety ratings with less material used. However, evidence of budget limitations can be seen in the ring-structure connecting the upper and lower body. Rather than a full stamped piece requiring a very large and expensive piece of machinery, a section of the structure is attached using structural adhesive.

The importance of an 8% weight-loss is easily dismissed, until you drive a Fiesta and a Mazda2 back-to-back. Of the two, the Mazda has the dynamic edge, and despite meagre power output remains a joy to drive. Best of all, the optimist could choose to see Mazda’s weight goals as marking the point at which safety-driven model bloat hit its apogee and we began moving towards a lighter future where 160hp four-bangers were more than merely adequate.

More than that, the SKYACTIV-chassis’s focus on driving dynamics has resulted in further improvements to handing with a quickened steering rack combined and increased positive caster. The difference in the steering is readily evident; not heavy but much more direct.

However, the realist will note that weight-loss and chassis improvements aren’t enough. Only a minor fuel-savings will be realized by the SKYACTIV chassis and body. The major difference will come from drivetrain improvements.

Don’t look for anything radical in the transmission department. With great pragmatism, Mazda has noted and rejected the cost of developing a dual-clutch gearbox, spurned the non-involving fuel-savings of a continuously terrible – er – variable transmission and gone instead for refinements of the good old auto and manual transmissions.

The changes to the manual are clever, but slight. Minor adjustments to throw-length and some weight-savings realized by trickery such as a shared input gear for first and reverse show a general improvement, but Mazda’s stick-shifts are generally quite good anyway.

It’s with the automatic tranny that Mazda’s pulled a fast one. One need only look at the mixed reviews of Ford’s six-speed dual-clutch or check the recall list on the VAG DSG to see the pitfalls of pouring money into a completely new tech. Mazda has taken what seems to be the easy route here, re-jigging the venerable automatic gearbox with a more direct feel that’ll keep the enthusiast happy.

That’s perhaps an oversimplification, but with a greater lock-up range and a modular unit containing calibrated hydraulic controls, the new 6-speed auto feels much more in tune to what your right foot is doing, particularly on tip-in.

So we have bundled development and a focus on honing simpler technologies rather than chasing pie-in-the-sky tech. Time to get back to Niinai-san and the SKYACTIV engine suite, where both ideas combine for some real-world fuel savings.

SKYACTIV-G and -D engines have, respectively, both the highest compression ratio for a production gasoline engine and the lowest compression ratio for a diesel engine. For both, the concept is the same: hybrid vehicles are all well and good, but people keep buying cars equipped with nothing more than a trusty old internal combustion engine. Even with a market shift more towards electric and hybrid drivetrains, the bulk of the vehicles on the road are still going to be ICE-equipped.

Thus, improving the combustion cycle in both diesel and gasoline applications is going to affect passenger car sales right now, especially as Mazda doesn’t appear to intend a premium charge for their SKYACTIV technology. Rather, next year’s Mazda3 will bow with a SKYACTIV-G engine and the improved transmissions as the standard equipment on mid-range models starting sometime in October.

The availability of SKYACTIV-D remains nebulous, although it could appear in some Mazda products as soon as next year. This twin-turbocharged diesel boasts improved torque from a combustion cycle that ignites much closer to top dead centre, giving a longer power-stroke. Multi-hole injectors allow for a more homogenous fuel-air mixture and the low compression ratio allows for more precise timing control.

Why doesn’t everyone run their diesel engines this way? Among other issues not outlined, Mazda’s engineers needed to overcome cold-start problems with variable valve-lift. As much as I hate the phrase, it’s a paradigm shift: the low compression means thinner con-rods and a lighter rotating assembly that revs higher; this is a diesel that redlines at (and pulls to) 5200rpm.

However, it’s the SKYACTIV-G that you’re more likely to get a chance to drive in the near future. Want some good news on the efficiency front? How does 13:1 compression and a 4-2-1 header strike you?

That’s right, moving in a completely different direction than other manufacturers, Mazda has put together a hi-po four-banger that gains 15% torque across the rev range while still getting better fuel economy. It’s a sprightly little engine and noticeably more potent at low revs.

How do they get away with a compression ratio higher than a 458 Italia in a four-cylinder that runs on regular gas? Control the burn. That header is designed to maintain consistent temperature levels in the combustion chamber, and the SKYACTIV-G features special piston cavities which allow for rapid and even flame-front propagation. Those multi-hole direct injectors are at work here again, although there’s a limit to the tech. Overseas versions will be running 14:1 compression, but North American fuel requirements dictated a detune.

The next-gen Mazda3 will only be partially SKYACTIV, lacking the chassis and body upgrades that will first be fully available in the CX-5 crossover (which you’ll be glad to note will be available with manual transmission). With this partial first wave of improvements, Mazda is reporting attaining 40mpg on the highway.

Revolutionary? The numbers don’t seem so. But it’s competitive, and the comprehensive focus that Mazda is bringing to its entire lineup shows a different strategy than that behind a low-volume halo car like the Nissan Leaf.

Let’s face it, people are going to continue to buy Mazda products based on the way they drive. If Mazda can reduce consumption to the point at which a enthusiast looking for an engaging drive doesn’t end up paying a penalty at the pump, they’ll have a success story on their hands.

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2 of 45 comments
  • Dwight Dwight on Aug 23, 2011

    SKYACTIV is what they came up with to promote cars with fuel economy that will just be on target with the competition? Come on, now. All they have to say is Gas Direct and promote a 40+ mpg on their cars and perhaps they'll sell a few more. From what I understand, we'll have to pay more for SKYACTIV than their standard engines. So you'll have to pay a premium to get fuel economy that is on par with a base model Civic. That makes sense.

  • Elusivellama Elusivellama on Aug 25, 2011

    Owner of a 2010 MS3 here. I'd be most interested to see how SkyActiv can be added to the Speed 3 when the 3rd gen rolls around. What I'd love to see: - updated 2.3L DISI using SkyActiv technology - updated 6 speed SkyActiv tranny - weight reduction across the board - better factory motor mounts (not a real big deal, aftermarket motor mounts tend to be better anyway) - Kodo design language (my black MS3 actually looks pretty sharp if you see it in person, and so do red MS3s, but I weep for the other colours) - better handling But damn this car is still fun to drive! This Jinba-Ittai philosophy is 100% evident when you start to toss the car around corners and such.

  • Dusterdude @El scotto , I'm aware of the history, I have been in the "working world" for close to 40 years with many of them being in automotive. We have to look at situation in the "big picture". Did UAW make concessions in past ? - yes. Do they deserve an increase now ? -yes . Is their pay increase reasonable given their current compensation package ? Not at all ! By the way - are the automotive CEO's overpaid - definitely! (That is the case in many industries, and a separate topic). As the auto industry slowly but surely moves to EV's , the "big 3" will need to be producing top quality competitive vehicles or they will not survive.
  • Art_Vandelay “We skipped it because we didn’t think anyone would want to steal these things”-Hyundai
  • El scotto Huge lumbering SUV? Check. Unknown name soon to be made popular by Tiktok ilk? Check. Scads of these showing up in school drop-off lines? Check. The only real over/under is if these will have as much cachet as Land Rovers themselves? A bespoken item had to be new at one time. Bonus "accepted by the right kind of people" points if EBFlex or Tassos disapproves.
  • El scotto No, "brothers and sisters" are the core strength of the union. So you'll take less money and less benefits because "my company really needs helped out"? The UAW already did that with two-tier employees and concessions on their last contract.The Big 3 have never, ever locked out the UAW. The Big 3 have agreed to every collective bargaining agreement since WWII. Neither side will change.
  • El scotto Never mind that that F-1 is a bigger circus than EBFlex and Tassos shopping together for their new BDSM outfits and personal lubricants. Also, the F1 rumor mill churns more than EBFlex's mind choosing a new Sharpie to make his next "Free Candy" sign for his white Ram work van. GM will spend a year or two learning how things work in F1. By the third or fourth year GM will have a competitive "F-1 LS" engine. After they win a race or two Ferrari will protest to highest F-1 authorities. Something not mentioned: Will GM get tens of millions of dollars from F-1? Ferrari gets 30 million a year as a participation trophy.