Mazda’s Legacy of Engine Innovation

Mazda has a unique history when it comes to its engines. While most auto manufacturers are content to stick to the usual time-tested engine technology, a quick look around your local used Mazda dealership will tell you that this is a brand that has never been afraid to break new ground and take some risks. That’s manifested throughout the company’s history and continues into the present day with a new breed of ultra-efficient SKYACTIV engines.

Mazda went back to the drawing board to design the SKYACTIV engines, utilizing some emerging technologies and engineering around issues that have proved too much for other automakers. The work paid off, with Mazda introducing the world to a new breed of fuel-friendly engines in 2011. Designing an entirely new series of engines, along with a host of other efficiency-improving SKYACTIV vehicle tech, might seem like an ambitious way to meet increasingly stringent efficiency guidelines, but given Mazda’s track record for innovation, it comes as little surprise. Let’s take a closer look at Mazda’s SKYACTIV technology, figure out who exactly makes Mazda’s engines, and then explore another ambitious engineering experiment from the automaker’s archives: the Wankel rotary engine.

The Sky’s the Limit

SKYACTIV isn’t just a line of cutting-edge engines: it’s also an entire suite of efficiency-improving technology. This includes new vehicle bodies, chassis, engines, and transmissions, all designed from the ground up to provide some of the best fuel efficiency around. Engines range from the gas-powered SKYACTIV-G, diesel-powered SKYACTIV-D, and the innovative SKYACTIV-X, a first-of-its-kind gas engine that uses homogeneous charge compression ignition (HCCI).

First unveiled on the 2011 Mazda2, the SKYACTIV-G is a direct-injection gas engine with a higher-than-average compression ratio of 13:1. This increased compression has a direct impact on the engine’s fuel efficiency which, along with a host of additional upgrades throughout the drivetrain, allow SKYACTIV engines to offer impressive fuel economy without a noticeable drain on performance. The SKYACTIV-G, the brand’s gas-powered SKYACTIV offering, features all-aluminum construction and low-profile, dome-shaped cylinder heads with a small indentation on top, allowing for increased compression and a richer fuel-air mixture.

In addition to the engine itself, SKYACTIV-G engines feature a unique 4-2-1 exhaust manifold which further improves efficiency by dividing the pressure created by each cylinder head. This has the net effect of increasing the speed at which exhaust gasses are released which, when it comes to fuel economy, is always a good thing. Lastly, SKYACTIV tech extends to the transmission, where Mazda has opted to lighten the entire assembly by almost 90 pounds on AWD models. Less weight translates into a more efficient vehicle, which means a smaller carbon footprint and fewer visits to the gas station. Mazda’s SKYACTIV-G engine comes in four different sizes, from a 1.3-litre to a 1.5-litre, 2-litre and 2.5-litre setup. The 2.5-litre can even be paired with a plug-in hybrid system on the Mazda CX-60, giving drivers the best of both worlds and offering some of the leading fuel economy while still delivering a combined 323 horsepower and 369 lb-ft of torque.

SKYACTIV-D is a line of turbocharged diesel engines that, unlike most diesel engines, use lower compression to reduce emissions. The idea of a low compression diesel has been around for a while, but the technology has always been hindered by its tendency to cause difficult cold starts. Mazda engineered around the issue by installing piezoelectric fuel injectors with nozzles that can change the spray pattern to produce the ideal coverage for a range of conditions. Exhaust valves also stay open longer than usual when the engine starts, with these hot exhaust gasses making it easier for the engine to warm up.

The SKYACTIV-X engine might be Mazda’s most ambitious project to date, relying on an entirely new technology to deliver unsurpassed fuel efficiency. Homogeneous charge compression ignition (HCCI) is a system in which the engine’s fuel-air mixture is ignited not by the spark plugs but rather compressed by a small, separately-ignited fuel charge. This trick gives the SKYACTIV-X an unheard-of compression ratio of 16:1, resulting in 20 to 30 percent better fuel efficiency. This requires the engine to use specialty spark plugs with Spark Controlled Compression Ignition (SPCCI) technology to get around the ignition problems presented by the unusual compression ignition design, but the results speak for themselves. Currently only available as a four-cylinder engine in 2.0-litre and 3.0-litre sizes, Mazda is reportedly developing a new inline-six version for use on the fourth-generation Mazda6 and CX-60.

But who makes these engines? There’s been a little bit of confusion concerning some old business partnerships, so let’s clear things up once and for all. Ford has long maintained a partnership with Mazda and, at one point, owned as much as 30 percent of the Japanese automaker. This was a mutually beneficial setup for both entities, allowing Ford to gain a foothold in the Asian market and Mazda to pick the brain of one of the world’s most storied automakers. Until recently, the two brands were partners in the Changan Ford Mazda Engine Co., Ltd. in Nanjing, China, which produced 1.5, 2.0 and 2.5-litre versions of Mazda’s SKYACTIV engines along with the Chongqing Changan Automobile Co., Ltd.

That relationship came to an end in 2019 when Mazda bought out Ford’s stake, changing the name to Changan Mazda Engine Co., Ltd. but changing little else. The factory employs over 1,200 workers, producing 430,000 SKYACTIV engine units per year in a joint partnership between Mazda and Chongqing Changan Automobile Co., Ltd. That’s not to say that Mazda is done partnering with rival brands as a whole: in 2015 Mazda entered into an agreement to provide SKYACTIV engines to Toyota, which will reciprocate with its own hydrogen fuel cell systems.

A History of Innovation

First devised by German engineer Felix Wankel in 1929, the Wankel engine is a type of internal combustion engine (ICE) that ditches the reciprocating piston design common to most internal combustion engines in favor of a three-sided rotor. This rotor is constantly moving in one direction to produce power, as opposed to a piston in an ICE which moves in one direction on the downstroke and the opposite direction on the upstroke. Picture an oblong chamber and a rotor that looks something like the triangular planchette from a Ouji board, and you’ve got the idea.

The more fluid nature of this design holds a number of advantages over a typical ICE setup, allowing for a smoother, more compact engine that offers a better power-to-weight ratio, higher RPMs, and, therefore, more power than normal engines. Because power is fed directly to the output shaft, Wankel engines don’t need connecting rods or traditional crankshafts, further reducing their size and complexity. They can also take a much lower octane fuel without any of the knocking or pre-ignition such grades can often cause, and their iron rotors and aluminum housings mean greater thermal expansion, making them virtually seize-proof.

With all these benefits, you might be wondering why every vehicle on the road doesn’t have a Wankel engine under the hood. Despite all its advantages, the Wankel was never the most efficient design on the market. The engine’s oddly-shaped combustion chamber is great at delivering uninterrupted power, but not so great at maintaining thermal efficiency. The Wankel design also tends to burn through oil, and this, combined with the fact that it tends to allow a lot of unburnt fuel to exit through the exhaust, is a recipe for disaster in an increasingly emission-conscious world.

Mazda wasn’t the only auto manufacturer to embrace the Wankel design, with brands like Ford, GM, Nissan, Rolls-Royce and Mercedes-Benz all experimenting with the concept. Mazda was, however, the only manufacturer to ever produce a significant number of vehicles with Wankel engines. The Wankel concept fascinated Mazda engineers and executives alike, and the company was one of the first to embrace the technology with the debut of the Mazda Cosmos 110S, a two-door coupe, in 1967. The brand soon followed up with a Wankel-powered bus and pickup truck with customers quickly won over by the engine’s smooth operations. This early success was encouraging for Mazda, which was readying itself to switch to a fully Wankel-equipped lineup, but then the gas crisis came calling. Fuel efficiency is one area where the Wankel design can’t compete with standard ICE, and as gas prices continued to rise, the Wankel’s days in the sun were numbered.

But Mazda wasn’t done with the Wankel just yet. While its inherent inefficiencies meant it wasn’t a good fit for the brand’s main lineup, poor fuel economy has never been an issue in the sports car sector. In the 80s, the Wankel found a new home in vehicles like the RX-7 and, later, the RX-8, which featured an entirely new Wankel-inspired rotary engine called the Renesis. With 238 horsepower, improved fuel economy, and lower emissions, the Renesis was a huge marked improvement on the rotary engines of old, but still not enough to save the concept altogether: the RX-8 would be the last production vehicle in the world to feature a Wankel engine when Mazda abandoned the design in 2012 owing to it to increasingly restrictive emissions standards.

That’s not to say Mazda has given up on the concept entirely. Mazda’s new generation of engines includes one Wankel-inspired line in the SkyActiv-R. Designed in a joint venture between Mazda and Toyota, the SkyActiv-R has yet to show up in a production vehicle aside from a cameo under the hood of the Mazda RX Vision Concept at the 2015 Tokyo Motor Show.

The decades-long Wankel experiment didn’t scare Mazda away from embracing alternative engine designs: in 1993, the brand introduced the Mazda Millenia 4-door sedan, which used an unusual Miller cycle engine. Originally conceived in the late 50s, the Miller cycle engine modifies the typical four-stroke cycle: intake, compression, power, and exhaust, by breaking the compression stage into two mini-stages that require the piston to compress less of the fuel-air mixture. This results in increased power and efficiency over a traditional four-stroke design allowing for the Millenia’s supercharged V6 to displace just 2.25 litres, rivaling many four-cylinder engines of the day. The novel concept didn’t make a huge splash with consumers, and the increased cost of the Miller cycle design-led Mazda to abandon the engine in 2002.

Try the SKYACTIV Engine for Yourself

Want to experience Mazda’s game-changing SKYACTIV engine for yourself? The team at LA Mazda is here to answer any questions you might have about this ultra-efficient engine technology. Whether you’re looking for a traditional gas engine, diesel setup, or are curious about the cutting-edge technology behind the SKYACTIV-X, there is no shortage of options here at the showroom. In addition to our wide range of new Mazda vehicles, we feature some of the best models from the recent past, as well as a generous lineup of used and certified pre-owned vehicles from a variety of automakers.

For drivers who don’t have time to stop by the dealership at 6217 50th Street in Leduc, our website allows you to complete virtually every aspect of the car-buying process right from the comfort of your own home. Search the inventory, build, and price your own custom vehicle, value your trade-in and apply for financing without leaving your couch. When you’re ready for a test drive, we’ll be here for you, ready to hand over the keys and answer any questions you might have. It’s just part of our commitment to taking the stress out of what can be a notoriously tough process by offering unparalleled selection, auto service, and support every step of the way.