First Drive: 2012 Mazda3 SkyActiv-G

October 24, 2011 By Jonny Lieberman | Photos Michael Shaffer- Motortrend

Mazda is about to face an interesting dilemma. It just released the slightly less smiley mid-cycle refresh of its C-segment sleeper, the Mazda3. How important is the 3 to Mazda? In the U.S., the little sedan/hatch accounts for fully 40 percent of Mazda’s sales. Worldwide, one out of every three Mazdas sold is a 3. In fact, the best-selling car in Canada (of all places) is the Mazda3. As you can see, messing with the 3’s formula could very well prove perilous for Mazda’s bottom line. But the Mazda3 is better than ever, and you can now get it with the all new and technically intriguing SkyActiv engine and transmission(s). What’s the dilemma then? Keep reading.

As of 2012 you can buy the Mazda3 in six flavors. Two versions (the i SV and i Sport) come with the standard, carryover 148 horsepower MZR 2.0-liter I-4; two versions (i Touring and i Grand Touring) with the fancy new 155 hp SkyActiv-G motor, one with the big-bore (ha!), carryover 167 hp MZR 2.5-liter I-4 (that’s the s Grand Touring); and one last version — the mighty Speed3 — with a turbocharged 2.3-liter four-banger with an impressive 263 hp and a whopping, diesel-like 280 lb-ft of torque. It gets even more confusing when you start factoring in that some engines only come with the four-door body style, but let’s not get bogged down with that. For now, let’s worry about SkyActiv and why Mazda felt the need to come out with an engine that makes just 7 horsepower more than the 3’s entry-level mill. Especially as Mazda claims this new engine will account for more than 50 percent of all Mazda3 sales. Hence the dilemma.

What then is SkyActiv, aside from a word hated by spell checkers and copy editors everywhere? Mazda claims it’s a whole new way of thinking. A new automotive philosophy, if you will. Let’s look at the new six-speed SkyActiv automatic transmissions to illustrate their point. Starting with a “blank slate and an open mind,” Mazda engineers listed the ideal attributes of an automatic transmission. Quoting the PowerPoint slide, they are: high efficiency; direct connected feel; quick, responsive and smooth shifts; easy low-speed control; and smooth, powerful launches. Then they looked at which types of transmissions give you those attributes. Without getting too deep into their marketing matrix, dual-clutches are heavy, inefficient, and jerky at low speeds; CVTs are inefficient at high speeds; and traditional autos feel like mush.

The idealized Mazda transmission turned out to be a little from column A and a little from column B, namely a multi-plate clutch and a torque converter. And since each is smaller than they would be in a conventional automatic transmission, Mazda is able to pack in a larger damper that cuts NVH. Working in unison, this combo nets 7 percent greater fuel economy, more direct shifts, and much quieter operation. In conjunction with the new SkyActiv-G engine and some aero tweaks, the 2012 Mazda3 automatic is 21 percent more efficient than the car it replaces (the manual equipped car is only 18 percent more efficient because manuals are quite efficient to begin with). Meaning the four-door Mazda3 with SkyActiv technology can achieve 40 mpg. Of course, that’s what Mazda claims. Here’s what Frank Markus, my colleague and director of all things technical at Motor Trend, found:

“To put the new SkyActiv’s lofty 40-mpg highway fuel economy number to the test, we loaded up a Mazda3 i Grand Touring model with long-weekend gear for two people and drove from Detroit to Boston. The route included 1500 miles of mostly expressway driving posted at 65 mph, and we maintained pace with the left-lane traffic at 10 over. While in Boston we probably racked up 20 miles worth of frustrating maneuvering around the horse-era network of mainly one-way (usually the wrong way) streets and tunneling freeways.

Our mid-October timing meant the fall colors were at their peak and the temperatures were crisp enough to leave the A/C switched off. Steady speeds, minimal accessory loading, and mostly dry pavement make this trip a pretty ideal test. The onboard computer read 37 mpg at an average speed of 57 mph for the entire trip, and after the final fill-up our off-board calculator spit out a figure of 35 mpg. OK, maybe the difference is attributable to the roughly 7 additional horsepower we expended per mile by running above the limit. Perhaps 40 mpg demands greater driver patience.”

Perhaps. Though it must be pointed out that an observed 35 mpg at mostly 75 mph with a little bit of city thrown in is pretty dang decent, and probably on par with what you’ll get in the real world from the 3’s high-mileage competitors. And by “high-mileage competitors” I mean the Honda Civic HF as opposed to the regular flavor Civic. The Chevy Cruze Eco instead of the standard Cruze. See what I’m getting at (and what Mazda pointed out a few different times)? Mazda’s mainstream volume player that will account for more than 20 percent of all Mazdas sold in the U.S. will achieve the same mileage as special high-mpg variants from the big players. In terms of total American Chevrolet sales, what percentage will the Cruze Eco represent? A teeny, tiny drop in the proverbial sales bucket, that’s what. Only the mainstream Hyundai Elantra claims such big mpg numbers for a regular product.

Now, my driving experience was a bit different from Frank’s. In my estimation, there are only two volume manufacturers in the world that go out of their way to bake sportiness into every product they make. One is Porsche, and the other is Mazda. As such, Mazda planned a ridiculously complex drive route for us that just happened to be over and across some of my favorite Southern California canyon roads to prove the Mazda3’s sporting nature. Keep in mind this car is one step up from Mazda’s bottom-rung sedan and hatchback. That said, the chassis was composed, the handling was neutral, and even though I was driving the automatic transmission, I was having fun. The engine, while not overwhelming in a straight line (0-60 mph happens in 7.8 seconds), was torquey enough to keep the speed up into and around fast corners. I kept thinking to myself, “Why would anyone bother with the 2.5-liter?” And, true to what Mazda claimed, the automatic did shift pretty quickly in manual mode. About as fast as a DSG-equipped Volkswagen, by my estimation.

Then something odd happened.

My driving companion’s wife had a baby seven days earlier. A fellow L.A. native, he figured the baby slept all day anyway, and a man’s gotta work. There we were, lost up in the Angeles National Forest, and he gets a message: something’s wrong, wife and newborn are headed to the emergency room. There’s a brief moment of silence before I offer that of course I’m willing to bail out on the program and get him to Pasadena. We set off and I call a Mazda engineer to explain why I’m aborting their program. For the next 40 miles I don’t go below 80 mph, and once we got out of the canyons and onto the freeway I rarely went below 100 mph. The good news? His wife and son are totally fine (just a scare) and the Mazda3’s trip computer showed 26.7 mpg.

We should talk engine, as the totally rethought SkyActiv-G engine is the second part of the SkyActiv puzzle in the 2012 Mazda3. In its purest, European form, the SkyActiv-G 2.0-liter features an almost impossibly lofty 14:1 compression. How does Mazda achieve this without near-constant knocking and/or black soot shooting out into the atmosphere? Like the new automatic transmission, plenty of good old engineering. Or should I say good new engineering? First, the fuel is delivered into the cylinders via direct injection at 2900 psi. Yes, for a non-diesel, that is quite high. Moreover, the SkyActiv direct injection fires not one, but two blasts of fuel into the cylinder (once during the intake stroke, once during compression) per cycle. The initial squirt of 91 octane cools the cylinder to prevent knock.

Did I say 91 octane? So yeah, over in fancy pants Europe you can get a Skyactiv-G that takes 91 octane. However, here in America, Mazda sees premium fuel as a barrier to sales. Therefore the Mazda3 with SkyActiv-G we get runs on 87 octane. Meaning that Mazda had to lower the compression ratio to 13:1. Er, whoops, that’s not true. That’s going to be true on the upcoming CX-5 with its trick 4-2-1 exhaust header. But since that header would require altering the Mazda3’s firewall, engineers had to use the exhaust system that’s already there and lower the compression ratio to 12:1. Now, before you start freaking out, I’d like to point out that the Ferrari 458 Italia also has a 12:1 compression ratio (fine, 12.5:1). Thing is, 12:1 on 87 octane is pretty remarkable. And that’s the really cool thing about this whole SkyActiv program — we ain’t seen nothing yet. Back to Frank:

“This initial SkyActiv fitment seems to work well and whets my engineer’s appetite for the next generation, which promises to include a homogeneous-charge compression-ignition (HCCI) combustion system. The idea is to combine the lower cost architecture and simpler emissions of a gasoline engine with the unthrottled compression-ignition efficiency of a diesel by shutting off the spark plug under steady-state low-load operating conditions while burning gasoline the whole time. It’s a combustion-control electronics nightmare, but when these hurdles are overcome, the technology promises to rival the performance and economy of a more expensive downsized turbo. The more ways there are to skin that cat, the better.”

Hard to disagree with that. Moreover, Mazda claims that unlike the refreshed 3, going forward all their new products will feature SkyActiv (remember, that means clean sheet design) technology across the board. Engines, transmissions, suspensions, you name it. Why the big push? Unlike the aforementioned volume players like GM and Honda, Mazda simply doesn’t sell enough cars for hybrid technology to make any economic sense. Remember, hybrids account for a tiny fraction of the overall car market, so Mazda would be chasing a fraction of a fraction. Instead, its cars are going to be more fuel-efficient using mainstream though totally improved technologies. Speaking of which, they won’t say which model specifically, but within 15 to 18 months, Mazda will have a diesel passenger vehicle on sale here in America. We’re betting it’s the CX-5 with SkyActiv-D. Here’s to more and more innovation from our friends at Mazda.

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