Road Test

Road Test: 2011 Mitsubishi i-MiEV

August 8, 2011

Mitsubishi i-MiEV 2011_01Here is the perfect city car. The new Mitsubishi i-MiEV. i-MiEV is a plug-in electric car and it’s quite superb. It’s quiet and enviromentally friendly, drives smoothly and comfortably, can accomodate four adults, is easy to park in the city and most of all, it is very fun to drive. The elctric motor in the i-MiEV develops 67 horsepower, which sounds awfully little. But it also develops 180 Newton metres of torque, which is available instantly, right from the zero up to 2000rpm. This makes the driving with the i-MiEV very fun in the city traffic. Because the electric motor has a high torque output and it can spin 8000rpm, it requires only one gear.

The transmission includes a conventional differential but no reverse gear is required. When R (reverse) is selected, the electric motor just spins in the opposite direction. So technically this car could go as fast backwards as it does forwards, but luckily Mitsubishi has limited the top speed. When driving forward the top speed is 130 km/h, and when driving with the reverse, it’s probably a bit less. i-MiEV goes easily even on the motorway, but the city this cars favorite place. Without any gear changes, acceleration goes very smoothly. When you press the acceleration pedal, there is no lag but the electric motor is always ready to go. With a lot of torque available right from the zero revs and because no gear changes are needed, i-MiEV can accelerate from standstill quite nicely. It’s nice to surprise some other drivers on the road, who seem to think that electric cars are very poor with their performance.

i-MiEV has a very efficient regenerative braking. When the accelerator pedal is released, the motor functions as a power generator, converting the kinetic energy into electricity to recharge the traction battery. The level of this “engine braking” effect can be varied by selecting one of the three driving modes from the gearshift. D mode is for urban driving, tuned to be energy efficient. B mode increases regenerative braking even more and can be used in the city or during downhill driving. C mode decreases the regenerative braking to offer a smoother driving experience. Especially with the B driving mode, the i-MiEV can drop its speed quite fast when the acceleration pedal is released without the braking lights coming on. This should be noticed when driving in the city and someone is driving very close to the rear. Otherwise the regenerative is a great feature and when you get use to it, you don’t need to use the brake pedal as much any more.

The only bad thing in the i-MiEV is its short driving range. With a full charge, you have a driving range of 150 kilometres (94 miles). Although in reality, it seems that something like 120 kilometres (75 miles) is more realistic. Using the air condition or the heater drops the driving range even more. On the display there is a large digital speedometer and the Energy Usage Indicator. If you would like get a longer driving range, you should try to keep the needle in the Energy Usage Indicator within the green ’Eco’ zone while driving. Releasing the accelerator or braking moves the needle into the blue ‘Charge’ zone. On the display there is a small circular screen that reports the status of the traction battery charge in 16 segments. A low energy warning indicator flashes when only 2 segments remain visible. This screen also displays the gearshift lever position. the driving computer display can be found from the other small screen. It shows the driving range remaining on current traction battery charge level, which is calculated on energy consumption over the last 15 miles. This Range Remaining display is very useful, when planing the next moment to charge the traction battery pack.

The traction battery pack powers the electric motor, air conditioning and cabin heater. Other devices are powered by a conventional 12V auxiliary battery, charged by the traction battery via a DC-DC converter integrated with the on-board charger. The traction battery pack is located below the i-MiEV’s floor. It consists 88 lithium-ion 3.7V/50Ah cells connected in series to deliver 330V/16kWh. There is alsa an inverter unit that converts the traction battery’s DC output voltage into a 3-phase AC supply required by the electric motor. The traction battery can be charged through a normal domestic electricity supply. There is an on-board charger which converts AC voltage to a suitable charging voltage for the traction battery. A full charge can take 6-8 hours. i-MiEV is supplied with a dedicated charging cable and the charging socket is located on the rear right-hand side of the vehicle. On the left side of the vehicle there is a rapid charging socket that is designed to be compatible with the standardised connector on the end of the rapid charging unit’s heavy-duty cable. If there is a rapid charging point available, i-MiEV can be charged from empty to 80% full  in just 30 minutes.

i-MiEV has a lightweight steel monocoque body. The car’s dimensions are quite compact, length 3475mm, width 1475mm and heigth 1610mm. The wheels are almost at the each corner of the car, so the wheelbase 2550mm is quite long considering that the total length of the car is only 3475mm. At the front axle i-MiEV has MacPherson strut, while at the rear there is a 3-link de Dion system. The electric motor is at the rear axle, so i-MiEV is a rear-wheel drive. i-MiEV has a low centre of gravity which clearly improves car’s driving dynamics. It not really a sporty, but quite fun to drive even aroound corners. i-MiEV is equipped with ABS and EBD and has also the traction control and the active stability control as standard.