Toyota has held off on significant development of battery electric vehicles, but has a clear internal idea of where each type of powertrain fits into a future fuel mix. It believes battery electric is good for short commutes and urban driving, PHEVs and hybrids for general use and longer distance and FCEVs for larger and heavier cars as well as heavy-duty transport.
One of just three fuel cell electric vehicles (FCEVs) available to buy here in the UK, the Toyota Mirai was launched back in 2014, bringing with it the culmination of the brand's work on fuel cells which began in 1992. Now, after reasonable success in markets where FCEVs are more viable – such as Scandinavia – Toyota's second-generation Mirai will soon hit the roads after a ground-up redevelopment.
At the heart of the Mirai is the fuel cell-powered electric powertrain. It has been built specifically for the Mirai's new GA-L platform, with the power converter and cell stack made smaller and lighter, whilst also bringing an improvement in performance. Find out about fuel cells and how they work.
The fuel cell stack itself sets a new record for specific power density, producing 5.4kW per litre which has upped the Mirai's overall power output from 153bhp to 172bhp and 221lb-ft of torque. The cell stack is also a whopping 50 per cent lighter than the previous version, and cold weather performance means it will operate at temperatures as low as -30C.
Other key elements of the fuel cell powertrain have been improved and lightened, with the DC-DC converter reduced in size by 21 per cent and weight cut by almost 3kg. Far more efficient silicon carbide semiconductors have been used; the air intake is now smaller and quieter and a new lithium-ion battery is far more energy dense as well as more compact than the outgoing unit.
Toyota has added a third fuel tank to the Mirai, meaning it now carries around 5.6kg of hydrogen vs. the old car's 4.6kg, but despite the modest increase, range has increased from 300 miles, to around 400. This 30 per cent increase shows that all of Toyota's efficiency measures have added up to more than the sum of their parts.
Underpinning the new Mirai is Toyota's modular GA-L platform which gives the car a lower centre of gravity and greater body rigidity. It's also allowed the placement of the fuel cell components to be such that a perfect 50:50 weight distribution has been achieved.
Suspension front and rear is multilink – a significant improvement over the previous car's MacPherson struts and torsion beam setup. This helps deliver better dynamics for what is a heavy car (c. 1950kg), as well as more comfort for those on board, despite the options being large 19 or 20 inch wheels on 55 or 45 (respectively) low-profile tyres.
Styling has been brought up to date with Toyota's current design language, also delivering better aerodynamics. A lower overall height by 65mm and full underbody cover are the chief reasons for these aero improvements. Despite being lower, the second-generation Mirai is slightly larger than the previous version, with the overall length up by 85mm and width up by 75mm. A 140mm increase in the wheelbase plus the relocation of the fuel cell stack from beneath the cabin floor to the front compartment has improved rear seat passenger legroom.
Toyota is targeting a ten-fold increase in sales of the Mirai – which is ambitious given how limited the hydrogen market is in most countries. To put that into perspective, some 11,000 first-gen cars have found a home across the globe with just 180 of them in the UK and less than 1000 in Europe as a whole. It's likely to make the biggest gains in Scandinavia, Korea, Japan and California and is hoping that the promise of a 20 per cent price reduction will tempt people into the Mirai rather than rivals from Hyundai and Honda. In the UK, the first Mirai was around £66k so we expect the new car to come in at just over £50,000. However, combined with our scant hydrogen infrastructure, the second-gen car is – unfortunately – likely to remain a rare beast.