Welcome again to the long-term test of the Toyota Mirai. I take advantage of the fact that a little more than a year ago we have it to tell you our feelings with him after the initial illusion of a new car. The general experience of having an alternative mobility vehicle is given not only by the vehicle itself but also by other agents that contribute to it. So, in these next posts, I will talk, in addition to the car, of how I have felt as a user of Toyota and the experience of coexisting with distribution networks that are just beginning to develop. From the beginning, I told you that the Mirai is a great car that unfortunately does not receive the support it should from the brand and refueling infrastructure. But I do not want to go into too much detail for now, so I’ll comment first on the general experience with the vehicle itself, and in particular, what we like most about the car safety use the best outdoor car cover.
Throughout the leasing period that we have with him, we have traveled almost 15,000 miles (about 24,000 km) and, as you would expect in a car so new and with little mileage, has not had any failure of its own that has led to the workshop. The Mirai has circulated through San Francisco’s cold, damp weather, through the scorching, dry, dusty heat of the California Valley and the sultry city of Los Angeles, and has never had a performance problem or loss of performance. However, in this year that we have with him, we have suffered a series of incidents caused by third parties that have caused the Mirai to spend a few days in the workshop. It’s what life sometimes has in the city. On one occasion, a screw that was fired by the wheels of a truck on the highway crashed into one of the radiators of the car causing a slow but progressive leakage of coolant, which in a few days led the fuel system to indicate failure in the feeding system and required Alba, who was at the wheel at the time, to stop the car in a safe place. On another occasion, a person hit the front of the car while trying to clear it downhill. The driver dropped his car too much and broke the Mirai’s license plate and affected the operation of the active cruise control radar. This fault had the Mirai four days in the workshop.
And the last time the Mirai had to go through a workshop was to fix a puncture that we found right after returning from the summer vacation. This repair was simple and when I took it to the workshop, they took advantage of the opportunity to do the 15000 miles review. Leaving these three incidents aside, the Mirai has proven to be a product in line with the fame of other Toyota products in terms of reliability.
Already entering the field of driving, one of the most remarkable things about electric vehicles is the torque available throughout the range of engine revolutions. The Mirai is no less, and the slightest touch to the accelerator pedal becomes a forceful acceleration. We are talking about 350 Nm, which although pales in comparison to the figures of a Tesla Model S (between 525 Nm to astronomical 1075 Nm), the truth is that they are enough to outrun most cars at the start of a stoplight. Here you have to make a technical point: unlike other battery-powered electric vehicles, as you know, the Mirai has a fuel cell that is responsible for obtaining electricity through hydrogen that comes from fuel tanks and the air that it gets from the environment. Regarding the batteries, the fuel cell has a certain delay in the delivery of electric power. To alleviate this aspect, the Mirai has a hybrid battery similar to that of other Toyota hybrids that is responsible for providing an initial current to the power unit while the fuel cell increases its delivery. As the vehicle accelerates, there is an overlap in the powers delivered by each of the energy sources. This process is completely opaque for the driver, that is, one does not perceive at a dynamic level when the battery gives the power delivery paper to the fuel cell. The flow chart allows you to see the battery and the fuel cell working together. The result is a continuous acceleration at all times. The only witness that the fuel cell comes into operation is the slight purr produced by the air compressor that feeds it and the flow diagram in the instrumentation. This is especially true if the “Power” driving mode is selected, which adjusts the sensitivity of the accelerator pedal and increases the power delivered by the hybrid battery. The result is a surprising start to the march.
Another aspect that I value a lot is his poise on the road. The Mirai is a heavy car (it has an empty mass of about 1850 kg, data sheet ) and, although its power plant and fuel cell do a great job to move it with ease and even a certain agility, the mass of the car is made notice when you lift your foot off the accelerator and begin to roll with a sail: it gives the impression that it will never stop. On the other hand, the suspension has such an adjustment that it allows isolating the irregularities of the asphalt without compromising the roll in curves. I suspect that this behavior is, at least in part, the result of a low center of gravity. An interesting facet of Maria does not have to worry about cold starts. As an engineer and lover of mechanics, whenever I start internal combustion cars cold I am scrupulously careful to respect the engine warm-up times, watching the critical parameters (water temperature, oil, engine load) before demanding the engine its service provision. Having bad habits in that aspect can affect the operation and the useful life of the motor.
With the Mirai, this does not happen. You can ignite and accelerate thoroughly without problems, and the car never gives the feeling that its benefits are undermined by environmental conditions. According to the instruction manual, in cases of extreme cold, the response and power delivered from the fuel cell can be affected (around 65% of maximum power delivered during 1 minute at -30C). It is an unusual situation for most drivers.
Pulse & Glide
For those who are familiar with the world of hybrids, there is an efficient driving technique called pulse & glide. This technique has the objective to keep the electric motor of the car running as long as possible and the thermal engine off to get better consumption. It consists of accelerating moderately using the combustion engine to, once reached the cruising speed, quickly lift the foot of the accelerator to then just caress it a little. This achieves that the power demanded is less than what the hybrid battery can provide. This tactic allows maintaining the charge of the battery in periods of acceleration and reserving it to maintain cruises, especially in flat terrains or with slight descending slope. Interestingly, in this aspect, the Toyota Mirai has a behavior very similar to that of its hybrid brothers of the brand. The thermal engine paper takes it, in this case, the fuel cell, which comes into operation under high power demand conditions. Therefore, applying the pulse & glide technique helps to stretch the autonomy a bit more.
Autonomy and time of refueling
It is undoubtedly one of the Mirai’s strengths in relation to electric vehicles powered by batteries. Depending on the driving style and the type of route, the Mirai has consistently given us autonomies ranging from about 270 miles to 310 miles (432 km and 496 km respectively) each time we have refilled the fuel tank. Although the last figure only occurs in ideal traffic conditions, this range gives a good idea of what it is possible to expect each time we refuel, being 285 miles a usual figure. In addition to these good numbers, the autonomy of the Mirai has proved to be remarkably resistant to the outside temperature and the demand for air conditioning of the car. Therefore, we have never failed to turn on the heated seats and steering wheel and heating on cold winter nights, nor have we spared the use of air conditioning. We always have the air conditioning activated in AUTO mode and we let the system decide at all times what to do. Some electric as the new Nissan Leaf in its version of 40 kWh does not have refrigeration in the battery and sometimes can overheat. With a recharge time of between 3 and 5 minutes, the fear of being thrown away (the so-called range anxiety ) disappears. This is especially true in days when an unexpected plan arises and we have to move a great distance from the pull: we go through the service station and we are ready for it. The fast loading time also allows fuel to be served to several vehicles in a short period of time, just as we have ever encountered.
On the other hand, fast fuel loading does not pose a problem for the performance or long-term performance of the vehicle, nor does it depend on the temperature of the system to function properly. Let me explain: in battery electric vehicles, the fast charge mode subjects the batteries to large charge currents that can degrade their long-term storage capacity. This is a phenomenon of which Tesla is aware and, therefore, their cars are equipped with software that reduces load currents as the battery ages to lengthen its useful life and limits the load current as a function of the temperature of the battery. Battery (see paragraph 0075 of the patent). This increases the charging time of electric vehicles as successive rapid charges are made, as well as the progressive heating of batteries, especially in electric vehicles with air cooling. As the battery heats up, there may be a decrease in the power delivered. These last two points contribute, in short, to making the experience of using more similar to what we have been used to with internal combustion vehicles: refueling the car and expecting maximum performance from it.
Interior and sound insulation
The Mirai is a silent car, and this is not only given by being an electric vehicle, but also by the remarkable acoustic insulation it carries. Already from the outside, it is appreciated that the work of soundproofing the car by Toyota is great. In addition to the two rubber gaskets that cars usually carry to soundproof and maintain the sealing of the passenger compartment, the doors have a rubber gasket that seals all the gaps, creating a closed space between the doors. This helps to reduce the sound due to air turbulence. Once inside the car, the use of insulating materials and the triple layer windows with acoustic insulation provide a feeling of tranquility while driving. Interestingly, the car has some thermal insulation that had never experienced in other vehicles. You can leave the car with a warm cabin on the street in winter before going, for example to a restaurant. After two hours and with temperatures between 5 and 10 degrees it still feels relatively warm inside. As for the materials of the interior, after a year of use, they do not present appreciable wear and tear: the seats are still very comfortable and there does not seem to be any misadjusted panel. In fact, of all the electric vehicles that I have tried or had the opportunity to travel (Nissan Leaf, Chevrolet Bolt, Tesla Model S), the Mirai seems to be the one that has a better interior. This perception could change in a few weeks when I will have the chance to try the Jaguar I-Pace.
If there is one thing that I would be left with, it is the feeling that this vehicle is designed for a much longer life than the period of three years of leasing will offer us. It is the first electric vehicle that I would not mind staying after the end of the lease period since the benefits offered are similar to those of a conventional vehicle and its daily use does not mean the driver changes habits. On the other hand, the Mirai has some drawbacks, as it is logical that it happens in every new product of its first generation. I will talk about these and also the treatment of the brand and infrastructures in the next entries. Stay tuned, this time it will not be long!