Toyota introduces second-generation Mirai fuel cell electric vehicle as design and technology flagship
For 2021, Toyota has fully rebooted the Mirai, originally offered in 2016, as a premium rear-wheel drive sports-luxury fuel cell electric vehicle (FCEV) with striking design, cutting-edge technology, more engaging driving performance and a significantly longer EPA-estimated range rating.
The 2021 Mirai is powered by the latest evolution of the brand’s advanced fuel cell electric vehicle (FCEV) powertrain. The new Mirai is one part of an electrification strategy that also includes Toyota’s current and future hybrids and upcoming battery electric vehicles (BEVs).
Built on the rear-wheel drive GA-L platform that also underpins the larger Lexus LS sedan, the 2021 Toyota Mirai makes a major design departure from the front-wheel drive first-generation version. The body is lower, longer, and wider, with its bolder stance accentuated by standard 19-inch alloy wheels.
A more powerful fuel cell system provides a more engaging driving experience than its predecessor. The rear-wheel drive layout and four-wheel independent suspension deliver a sports-luxury sedan driving feel, with greater handling agility than before, yet also with a more comfortable ride. The RWD layout also allowed for increased hydrogen storage to boost EPA-estimated range to 402 miles (Mirai XLE grade), a 30% increase over the first-generation Mirai.
Still 650V as in the first Mirai, the next-generation fuel cell stack in the new Mirai is about 20% smaller and 50% lighter than the previous stack, and so fits easily under the hood. The new, smaller stack allowed the switch to rear-wheel drive.
In comparison, the first-gen Mirai was FWD, and the larger stack was placed under a raised section of the passenger compartment floor.
A compact, lightweight power control unit is now integrated with the FC stack case, further reducing overall system size. Relocating the air intake manifold and optimizing the gas channel separator electrodes and seals has resulted in a 12% increase in power output over the first-gen stack (128 kW, up from 114 kW). That translates to 182 hp and 221 lb-ft of torque vs. 151 hp and 247 lb-ft for the first-gen Mirai.
In the 2021 Mirai, a lithium-ion battery is smaller and lighter (98.3 lb. vs. 103.4 lb.) and has higher capacity than the nickel metal-hydride battery used in the first-gen model (310.8v and 4.0 Ah, compared to 244.8v and 6.5 Ah in the earlier car). The more compact battery package fits between the rear seat and trunk, and the trunk can carry 2-3 golf bags. Cooling air for the battery is silently pulled in from the cabin.
In the Toyota Mirai, compressed hydrogen fuel is stored in three 10,000-psi carbon-fiber-reinforced high-pressure tanks: one mounted longitudinally in the center of the car; another mounted transversely under the rear seat, and a third below the battery. The three tanks together hold about 11 pounds (5 kg) of hydrogen.
An electric air compressor pressurizes the intake air, and a water-cooled intercooler reduces the temperature of the compressed air before it enters the FC stack. A water-cooled oil cooler integrated with the air compressor helps to provide reliability.
The intake system is designed to mitigate noise, which will be virtually unnoticeable to occupants. The inlet design and sound-absorbing material in the air cleaner prevent air column resonance. By necessity, the intake air for the fuel cell must be purified; the electret air cleaner element captures ultra-fine particles (PM2.5), and a charcoal filter removes chemical substances. The resulting air released from the system is cleaner than the intake air.
The 2021 Mirai features more advanced user and safety tech, including Toyota Safety Sense 2.5+. This latest generation of Toyota’s driver-assist technology suite includes Full Speed Dynamic Radar Cruise Control, automatic emergency braking, and Lane Keep Assist. In addition, Blind Spot Monitor with Rear Cross Traffic Alert is standard on the 2021 Mirai.
The switch to a rear-wheel drive platform delivers a “twofer” in the 2021 Mirai. The new layout facilitates the coupe-like proportions and bolder stance. At the same time, the new platform allowed for a roomier cabin with more usable space on the inside and in the trunk.
The 2021 Mirai features a larger body with more passenger room. Wheelbase, height, length and width are all increased over the first-generation Mirai. Weight increases by just 176 lbs., yet weight distribution improves to near 50:50, and the center of gravity is lower to significantly enhance handling agility.
Operation of the FC system and battery is seamless. Normal initial acceleration uses battery energy, just as a battery EV would. After initial acceleration, it smoothly transitions to FC+EV operation, and then fully to FC power to the EV drivetrain when cruising. As a result, the driver feels a natural, linear response to the accelerator.
Like a Toyota hybrid vehicle, the FC also sends electricity to be stored in the battery, and the battery is also charged by the motor-generator during deceleration. Direct current from the battery is converted into three-phase alternating current for the FC air compressor and the electric drive motor. In the 2021 Mirai, a second DC/DC converter augments the main DC/DC converter to respond to the auxiliary load increase.
The Mirai provides excellent everyday driving performance, for example accelerating from 25 mph to 45 mph in 2.8 seconds. The driver can tailor the driving feel via the Drive Mode Select switch, which offers ECO, NORMAL and SPORT modes. NORMAL provides an excellent balance between driving performance and fuel efficiency. Selecting ECO mode prioritizes efficiency by optimizing air conditioning operation, while SPORT mode quickens accelerator response and tightens steering feel for a more dynamic driving experience.
As on Toyota Hybrids, Predictive Efficient Drive can learn repeatedly traveled routes to optimize charging and discharging of the battery to help maximize fuel economy and driving range.
Luxury Car Chassis. To make the second-generation Mirai its new sedan flagship, Toyota based it on the GA-L platform also used for the Lexus LS sedan. (The LS uses a larger version of the platform.) The change to rear-wheel drive and resulting new layout for the FC system and EV powertrain yield a near 50:50 weight distribution, versus 58:42 for the front-wheel drive first-gen Mirai.
The high-strength platform provides the foundation for superb handling agility and an exceptionally smooth, quiet ride. Laser screw welding and adhesive structure bonding, proven on many other Toyota and Lexus models, are among the construction techniques used to give the Mirai a truly premium feel on the road.
The suspension is completely new and fully befitting a flagship luxury-sport sedan. Sophisticated multilink suspension replaces strut-type front suspension and beam axle rear suspension used for the first-gen Mirai. Suspension geometry and stiffness provide highly responsive, direct-feeling steering. The result is a much higher level of handling precision, giving the second-gen Mirai a distinctly sporting feel to match its future-looking powertrain.
Active Cornering Assist engages the stability control to reduce understeer in certain cornering situations. Hill Start Assist Control, standard for both grades, allows smoother, safe takeoffs from stops on hills.
Electric power steering delivers quick response, with a tight 38.6-ft. turning circle for easy maneuverability. Both the XLE and Limited grades are equipped with 19 x 8-inch alloy wheels and 235/55R19 all-season tires. The Limited in addition offers optional 20 x 8.5-inch turbine-style Super Chrome alloy wheels with 245/45ZR20 tires.
Mirai Safety. Toyota Safety Sense 2.5+ equips the 2021 Mirai to help avoid collisions or mitigate their impact. Also featured on other 2021 Toyotas, including the Camry and Highlander, TSS 2.5+ is the next phase in Toyota’s evolution of active safety systems. A number of functions that are part of the Toyota Safety Sense have been enhanced.
For starters, the Pre-Collision System with Pedestrian Detection (PCS w/PD), features multiple enhancements. By enhancing the system capabilities, it is now possible for the system to help detect not only the vehicle ahead but also a preceding bicyclist in daytime and even a preceding pedestrian in low-light conditions. TSS 2.5+ also enhances the PCS w/PD system with intersection support. At intersections, the system may detect an oncoming vehicle or pedestrian when performing a left-hand turn and may provide audio/visual alerts and automatic braking in certain conditions. Additional PCS functions include emergency steering assist, which is designed to stabilize the driver’s emergency steering maneuvers within their lane while avoiding a preceding pedestrian, bicyclist or vehicle.
Each Mirai comes equipped with Full-Speed Dynamic Radar Cruise Control (DRCC), which can activate the feature above 30 mph, have a system designed to perform vehicle-to-vehicle distance controls down to 0 mph and resume from a stop. DRCC also includes a new feature that allows for smoother overtaking of slower vehicles. If traveling behind a vehicle traveling slower than the preset speed, once the driver engages the turn signal and initiates steering input the system will provide an initial increase in acceleration in preparation for changing lanes; after changing lanes, the vehicle will continue acceleration until it reaches the preset driving speed.
Lane Departure Alert is designed to help notify the driver via steering wheel vibrations or audible alert if it senses the vehicle is leaving the lane without engaging a turn signal. When DRCC is set and engaged, Lane Tracing Assist (LTA) is designed to assist the driver by providing a slight steering force to help center the vehicle in its lane using visible lane markers or a preceding vehicle.
Additional TSS 2.5+ features include Automatic High Beams, which detects preceding or oncoming vehicles and automatically switches between high beam and low beam headlights. Road Sign Assist (RSA), which is designed to recognize certain road sign information using a forward-facing camera and display them on the multi-information display (MID). With DRCC engaged and activated, RSA can also adjust speed up to the posted speed limit if driving slower or down to the posted speed limit if driving faster than posted.
In addition to the TSS 2.5+ system, to help Mirai drivers change lanes with confidence, Blind Spot Monitor is designed to help detect and warn you of vehicles approaching or positioned in the adjacent lanes. Rear Cross Traffic Alert (RCTA) can offer added peace of mind by helping to detect vehicles approaching from either side while backing out and alerting you with a visual and audible warning.
Two-Grade Model Strategy. Toyota will offer the 2021 Mirai in two grades, XLE and Limited, rather than only a top-of-line mono-spec version as with the first-generation model. The new strategy will make the Mirai accessible to a wider market.
The Mirai XLE grade has a starting MSRP of $49,500—$9,050 less than the starting MSRP of the outgoing 2020 Mirai. An Advanced Technology Package, which includes Bird’s Eye View camera, front and rear Parking Assist with Automated Braking and front seat foot illumination, can be added to the XLE for $1,410.
The Limited grade has a starting MSRP of $66,000, with optional 20” Super Chrome Alloy wheels available for an additional $1,120. Both the XLE and Limited grades have a Special Color price of $425 for Oxygen White, Heavy Metal, Supersonic Red and Hydro Blue (Limited only).
Mirai XLE grade will have a starting lease price of $499 a month, while the Limited grade lease pricing starts at $549 a month. Special launch incentives will be available when this next-generation Mirai first goes on sale, including special finance rates, retail cash back and launch cash back.
Each Mirai comes with up to $15,000 of complimentary hydrogen. Extended ToyotaCare, good for three years or 35,000 miles, will come standard with each Mirai. Other owner benefits include roadside assistance for three years (unlimited miles), an eight-year/100,000-mile FCEV warranty on key fuel cell electric vehicle components, a complimentary rental experience for up to 21 days during the first three years of ownership, and much more.