Toyota’s futuristic Mirai is still stuck in the future
The fuel cell-powered Mirai cleans the air as it drives. Why hasn’t it caught on yet?
TO POWER the futuristic Mirai for 10,000 kilometres, Toyota’s engineers say you can make enough hydrogen from the yearly dung output of a single cow (imagine what you could get from a married one).
The Mirai, whose name is Japanese for “future”, runs on hydrogen fuel cells. These combine hydrogen with oxygen to make electricity, which then powers a motor that drives the car. The only emission is water vapour.
That sounds clean enough, yet the Toyota goes one better. “This car is basically a mobile air purifier,” Ryotaro Shimizu, the Mirai’s deputy chief engineer, tells The Business Times (BT).
The car’s filters and catalysers scrub the air clean of pollutants such as sulphur dioxide, nitrogen dioxide and ammonia. The Mirai even removes 99.5 per cent of PM2.5, the ultra-fine soot that is known to harm human health.
Like other fuel cell electric vehicles (FCEVs), the Mirai is an electric car at its core. The main benefit of using hydrogen instead of simply drawing power from a battery is speed: at a hydrogen refuelling station it takes less than five minutes to fill the Mirai’s three hydrogen tanks with 5.6 kg of the gas, enough to power it for more than 800 km.
Toyota staff are bullish about hydrogen for other reasons. It can be extracted from a number of sources, including seawater, so it is potentially unlimited in supply. It is easy to transport. It is easy to store and stable, whereas batteries tend to self-discharge over time. “It’s really the Swiss army knife of fuels,” said Prasanna Ganesh, who heads business transformation at Toyota Daihatsu Engineering & Manufacturing.
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But not everyone is a fan. Along with Toyota, BMW and Hyundai are fuel cell proponents, but other carmakers have chased the technology for decades with little to show for it. Ford, Nissan and Mercedes-Benz partnered on a fuel cell project that resulted in only one car, the Mercedes GLC F-Cell. It was only produced for a couple of years before being quietly dropped. Mercedes said the technology worked well but made the car too expensive to build.
Honda discontinued its FCX Clarity last year, and Volkswagen issued a statement in 2020 to say that when it comes to passenger cars, “everything speaks in favour of the battery and practically nothing speaks in favour of hydrogen.”
Yet, the Mirai shows that the technology is coming along nicely, at least for Toyota. The Mirai is already in its second generation, and having briefly driven both iterations, I’ve seen big improvements first hand.
The current Mirai is much quieter than the first model and better to drive, with superior traction and better steering feel. Its plush cabin wouldn’t look out of place in a Lexus. And though its powertrain is unusual, its controls are familiar for anyone to jump in and operate.
It also looks sleek in a classically sensual way, with flowing lines, slim lamps and a low roofline. That was important because the Mirai has to be an ambassador for hydrogen. “We simply wanted to make an attractive car, because you would prefer to drive a cool-looking car, right?” Shimizu said.
Engineers like him are working on more concrete goals. Over two decades Toyota has increased the power density of its fuel cell stack by 15 times. Compared to the first FCEV Toyota offered for sale back in 2008, the Mirai’s drive system costs 60 times less.
In fact, in the six years between the first Mirai and the current one, Toyota brought the cost of major components down by two-thirds, even though the car is now more powerful and energy efficient.
Yet, there could be a simpler way to utilise hydrogen gas while fuel cell tech develops. With only slight modifications, today’s engines can combust hydrogen. Toyota gave short rides to the press in the Corolla Cross H2, a concept car with a 1.6-litre turbo engine.
On a test run to demonstrate its ability to sprint to 100 km/h with ease, an engineer revved it heartily to 120 km/h, presumably for kicks. He told me the engine was only slightly different from a petrol one, making it cheap to build. Only its fuel delivery system and engine management software are modified.
The hydrogen hardware adds less weight to the car than Toyota’s own hybrid system typically does. As for safety, the hydrogen tanks are so strong that Toyota has shot them with guns to see what happens. The tanks survive, the bullets do not.
While refusing to commit to a single technology, Toyota seems to be building a hydrogen toolkit. The Mirai has existing hardware (a battery pack and the drive motor) from a Lexus model. Its fuel cell stack can power trucks or buses because engineers can simply combine them for more power. The Corolla Cross H2 uses the Mirai’s tanks, and its engine is from Toyota’s GR Yaris. The hope is that mixing and matching components this way can help to scale up the technology.
As for whether fuel cells or combustion is the best way forward, Toyota said both are needed.
“Both possess different characteristics. Both have merits and demerits, both have advantages and disadvantages, so we should put the right car in the right job,” Koji Sato, one of Toyota’s most senior engineers, tells BT.
Short-range city cars might be better off with a cheaper approach such as combustion, while trucks are better off with fuel cells.
But FCEVs are clearly still in their infancy. Over the years Toyota has sold only 19,000 of them, while it has put more than 20 million hybrid cars on the road.
The Mirai is named after the future, but still belongs in it for now.
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