Mazda’s two-car hydrogen fleet doesn’t feel futuristic, and it doesn’t feel like a science project. The RX-8 Hydrogen RE starts immediately with the turn of a key. There’s no waiting for it to warm up. And once the car’s on, there’s no whirring, no clicking, no hiss. There’s nothing to announce the hydrogen being combusted in the 1.3-liter rotary. It merely purrs a soft tremolo whirr.
That’s right: combusted. Instead of developing a fuel cell system, Mazda is running hydrogen through the four-stroke cycle. Doing so in a standard piston engine is difficult because hydrogen is highly combustible — it’s more than ten times more flammable than gasoline. So when hydrogen gets too hot in an engine — like when it passes valves or a sparkplug — it combusts prematurely and breaks things.
Likely unbeknownst to Felix Wankel, the rotary engine happens to be uniquely suited for hydrogen duties. Intake and combustion are in two different places, which keeps the hydrogen cool, and the distance between them allows Mazda to fit a larger, more accurate direct fuel injection system. Mazda has been putting rotary mills in U.S. consumers’ hands since the ‘70s, and development is cheaper. Another plus to using a rotary engine in the RX-8: When the hydrogen is all gone, press a button and it switches to gasoline on the fly. It’ll even make the change automatically, should you be too busy bombing down a mountain road to notice the fuel light. To switch back to hydrogen, you have to come to a stop. There’s no danger to going the other way while moving, but Mazda wants gasoline power used as a last resort.
The downside is power loss. The standard RX-8 makes 232-hp and 159 lb-ft of torque, whereas the hydrogen variant produces 107-hp and 103 lb-ft of torque. Range, at 62 miles hydrogen and 28 miles gasoline, isn’t very impressive, either. But get this: The RX-8 Hydrogen is fun. It makes moves like its gasoline counterpart, with quick responses and an intuitive feel. It even has a six-speed manual. You can heel-toe.
Surprised? You shouldn’t be. The RX-8 Hydrogen shares the majority of its components with the standard model — even its assembly line. In fact, with the decals removed, you’d be hard-pressed to spot a difference. On the road, the throttle response isn’t as crisp, but you won’t notice unless you’ve just climbed out of a standard RX-8. You might not even notice the extra 187 lbs., the total weight penalty for the hydrogen components.
If you think the range and power could be better, you’re right. The RX-8 Hydrogen RE is old hat. It’s been around since 2006, leased as a fleet vehicle in Japan. Combined, the fleet’s completed more than 60,000 miles. Mazda’s new entry is the Premacy Hydrogen RE Hybrid, essentially what we know as the Mazda5. It’s an evolution of the RX-8 that places the hydrogen-combusting rotary in a series hybrid setup, like the Chevrolet Volt.
Here, the rotary acts as a generator. The power it makes is converted to electricity and sent to an electric motor, which drives the front wheels through a reduction gear. With the aid of the electric motor, Mazda’s stop-start system, and regenerative braking, the Premacy can travel 124 miles on a tank, according to the automaker. It has plug-in capability, too, should you find yourself completely screwed without a hydrogen or gasoline station around.
While there’s no mechanical connection between the engine and the wheels, the rotary doesn’t just blare at you indifferent to your right foot. Mazda made sure its revs increase as you press the throttle to keep with its “Zoom-Zoom” philosophy. No, it’s not as fun as the RX-8, but it shows the potential for alternative fuel people-movers. The technology developed for the Premacy opens the doors to new options for Mazda, from plug-in hybrids to electric vehicles.
The Premacy is just warming up in Japan — its fleet leases started in March 2009 — but the RX-8 Hydrogen RE is beginning its world tour. Mazda is delivering a fleet of the sports cars to Norway’s HyNor project this summer. The plan is to make the 360-mile costal freeway from Oslo, the capital, to the port of Stavanger able to support hydrogen transportation. The greater plan is the Scandinavian Hydrogen Highway Partnership, which is seeking to build an infrastructure across Denmark, Sweden, and Norway.
The highway of the tomorrow? It’s fast approaching, and while it’s still unclear where hydrogen power fits into the equation, Mazda’s fuel-cell efforts show that the vehicles traveling on it don’t have to feel futuristic. More importantly, they might even be fun.