Often, picking best in show at any of the major auto shows can be a tricky proposition. Not so in Tokyo.
The runaway favourite of the 2015 Tokyo Motor Show of nearly everyone who clapped eyes on it was easily Mazda's RX Vision concept, a long and languid sports car like a Japanese Aston Martin, stretched out in Soul Red scarlet. It's wonderful, and best of all was the news that the car would be powered by (at least in concept form) a new generation of the rotary engine. Dubbed the Skyactiv-R, it would take Mazda's high-compression and clever injection technology from its workhorse reciprocating engines, and apply the technology to the much-missed rotary.
If you're like me, you immediately thought, "Great! Sooo, when's that going on sale, then?" Well, not soon I'm afraid. While the concept was indeed swoon-worthy, details were so limited as to be absent. Yes, this thing's supposed to be rear-wheel drive, but apart from that and the nebulous rotary engine, that's all we know. And also, while it's pretty hot for a concept, this is absolutely not what a rotary-engined car should look like.
The nose, for instance, is far too long. One of the chief characteristics of a rotary engine is its compact size when compared to a conventional reciprocating engine, so there's no need for an extra-long bonnet. If anything, Mazda's concept looks a bit like a reborn version of the Toyota 2000GT from the 1960s. A straight-six or a V-8 would make far more sense powering this thing.
And there's the problem. Sure, a minority subset of gearheads would love to see a return of the rotary engine, but would anybody else care? If this technology is so great, why does Mazda seem to be the only one interested in it? Is the company's apparent obsession with the funny little triangle motor simply a stubborn refusal to let go of a technology that has outlived its time?
If you go hunting through history, there are certainly red flags to be raised. The first rotary engines were designed by a German engineer named Felix Wankel, who would lend his name to the motor: hence, Wankel Rotary Engine.
It took ol' Felix some 30 years to go from patent to working prototype, but his complex design would pretty much die there. It was truly a rotary engine, with the both the rotor and its housing spinning freely - this created better balancing and allowed for higher r.p.m. Even so, in 1957, it made just 21 horsepower.
A second engineer, one Hanns Dieter Paschke, came up with a simpler, fixed-housing design. Wankel would say, "You have turned my race horse into a plough mare," but that's a bit unfair. After all, Paschke's version didn't require a complete engine teardown every time you had to change the sparkplugs.
This fixed rotor design would be the eventual modern version, and the way it works is somewhat odd. In a standard reciprocating engine, the power-stroke drives the piston downwards and turns the crank; it's not unlike pedalling a bicycle, in which an up-and-down motion is transmitted into rotary motion.
In a rotary engine, the piston is replaced by a triangular metal piece that zips around in an oblong combustion chamber, transmitting its spinning motion directly to the crankshaft by a ringed gear. It's an elegant solution in theory, and does away with connecting rods and the like. It is simple, and compact, and just the kind of thing you'd imagine would appeal to a German engineer. However, there are one or two problems.
Defunct manufacturer NSU embraced the rotary, working both in partnership and competition with Mazda to bring the first rotary-powered car to market. NSU got there first with the Wankel Spider (a great name for the car), and then the Ro80, a rotary-powered luxury car.
Wow! Wait, where's all that smoke coming from?
Unfortunately, one of the drawbacks to the rotary engine is its reliance on proper seals. Each point of the triangle undergoes enormous stress during combustion, and if your apex seals aren't properly hardened: kaboom. Most of the Ro80's engines went bust, and soon after the company folded. Eventually they were acquired and became part of Audi.
Mazda, on the other hand, spent a little more time getting things right. Led by an engineer called Kenichi Yamamoto, a team of 47 engineers worked tirelessly to figure out how to get the rotary to spin without consuming itself. Many inside Mazda thought the rotary division was wasting both time and money. However, with a breakthrough in shaping the apex seal to resist chattering and vibration worked, and the Cosmo Sport was born. It was Mazda's first real sportscar, and a symbol of what the company could do.
From there, the first-generation RX-7 arrived and began taking the racetracks by storm. As a racing engine, the rotary works well as its balance and ability to rev freely can be used to keep it in the powerband. If you look up footage from Westwood racing circuit in the 1970s, you can see RX-7s just scorching past heavier machinery with bigger displacements.
The pinnacle came with the third-generation RX-7, known among enthusiasts as the FD. If the Ferrari F40 is my favourite dream car, then the FD is the dream machine you could make a reality. It's pretty, fast, lively, agile, and (unfortunately) somewhat explosive.
The FD's sequential twin-turbocharging gave it a short shelf life, especially among those owners who were maybe a little careless with maintenance. It wasn't an easy car to own or drive, but that just added to the legend. It remains probably the best of the sports cars to come out of Japan during the heady period of the 1990s.
The RX-8 that followed it was something else; it's still a pretty good car, especially in the handling department, but the 2+2 layout and low torque weren't everyone's cup of tea. Add in high fuel and oil consumption and Mazda's last production rotary engined car faded out with a whimper.
In an age when a juggernaut like VW turns to software cheating to get their cars to pass emissions testing, do we really believe the rotary engine might return? If so, how's it going to get around its old problems of reliability and a thirst for fuel. When it's racing, the rotary makes great sense; on the street, it's often like trying to turn that race horse into a plough mare again.
However, there is perhaps an idea, though one that might not appeal to every Mazda rotary fan. Consider the BMW i8: nominally powered by a turbocharged three-cylinder engine, it uses electric engines and plug-in power to give a sports car performance that's futuristic and easy on the environment.
As a range-extender, the rotary engine is perfect: it's compact, it works best at a constant r.p.m., and it can even be mounted flat.
So, imagine that gorgeous shape fitted with the powertrain out of a rear-drive Tesla, but lightened up as much as Mazda can, and with a compact rotary engine fitted so that the range is effectively doubled. Or, use electric motors like the KERS systems used in Le Mans racing to make up for the rotary's lack of low-end torque. Maybe we'll need all that room under the nose after all.
Brendan McAleer is a freelance writer and automotive enthusiast. If you have a suggestion for a column, or would be interested in having your car club featured, please contact him at [email protected]. Follow Brendan on Twitter: @brendan_mcaleer.
