Mitsubishi i-MiEVText and images © eco-drive 2010-2012 unless otherwise stated. No reproduction without express permission.
Mitsubishi i-MiEV (pronounced 'eye-meev') is a rather distinctive Electric Vehicle (EV) based on the standard petrol Mitsubishi 'i' car from Japan of which 500 models were also sold in the UK from 2007. It is a 'conversion' in as much as it was re-engineered as an EV from a conventional vehicle, but these cars are now rolling off the production line in Japan as EVs. It is marketed in the UK & Europe by Mitsubishi and also as Peugeot iOn and Citroën C-Zero with mostly cosmetic and interior specification differences.
i-MiEV (Mitsubishi innovative Electric Vehicle) is a fairly tall, narrow car, but with a surprising amount of front and rear space for 4 adults, easily accommodating someone over 6'2" in the rear. Based on the i car, which was designed to fit the 'footprint' (and power) constraints of the dimunitive Japanese 'kei' car class, it achieves a clever use of space in a compact form. Using an aluminium space-frame construction, it tips the scales at just 1,110kg yet achieves a 4-star Euro-NCAP crash test rating.
The electric motor and drive electronics are under the
high boot floor, driving the rear wheels. The rarity of
rear wheel drive on an undeniably city car (few other
examples such as the Smart car use this layout)
liberates the steering geometry on the front wheels to
give a phenomenal steering lock which narrowly loses out
to a London black cab for its ability to make a U-turn
in the street! There are rumours that the original 'i'
car was the product of an ill-fated joint venture
between Daimler and Mitsubishi to make a 4-door Smart
car, so you can definitely see the connection.
The i-MiEV carries its lithium battery, a
more 'conventional' battery than that in the Nissan LEAF, made up from
modules assembled into a battery pack, underneath the
vehicle in a sealed tray leaving the interior space
The i-MiEV (like most EVs) has a single-speed
drive system and uses a conventional, automatic-style,
selector lever with Park, Reverse, Neutral, Drive, Brake and Comfort
positions. The Brake mode introduces a stronger
regenerative braking (or 'regen') function than the
modest amount in Drive or minimal amount in Comfort when
releasing the accelerator pedal. The Comfort mode is
intended to be used on open road running where you want
less 'retardation' when releasing the pedal: but you can
produce the same effect simply by keeping the pedal
Although the Comfort mode is largely unnecessary, the stronger regeneration Brake mode is useful in hilly terrain or intensive traffic, recouping good amounts of energy: a mode which the Peugeot/Citroën versions lack, theoretically giving i-MiEV a slightly superior range. Good use of 'B' (and driving with care) means that less of your braking uses the normal friction brakes which simply waste energy.
Driving the i-MiEV is
pleasurable if unremarkable: excellent all-round
visibility and a slightly higher than normal driving
position suit urban life and ease parking, though its
tall body and skinny (but Low Rolling Resistance) tyres
can make it a little skittish in cornering, especially
on poor surfaces. The relatively long wheelbase, with
the wheels right at the corners of the vehicle, means
that it doesn't 'pitch' too much under acceleration or
braking but the narrow 'track' means it can't straddle
speed bumps so it gets a bit bumpy and leans a lot in
those circumstances and the ride is quite firm.
Whilst the 49kW (66hp) motor power figure may not
sound like much (it's similar to the peak output of a
1.2 petrol engine) the near continuous torque of 180Nm
is more akin to the peak of a 1.6 TDi. Its
weight of around 1,100kg means that the torque gives it
surprisingly spritely acceleration which is more than
adequate to cope with city and town driving. The
published top speed of 80mph should not be taken as a
target, but more a reassurance that you can hit and
maintain 70mph if your normal route to
work/school/shops/home includes a few miles of motorway
or dual-carriageway. Constant higher speeds (above about
50mph) really eat into the range, as with most EVs.
Not enough energy
The autonomy or range on i-MiEV is on the low side of current
offerings. Despite the battery being
lithium-based, Mitsubishi have only installed
16 kiloWatt-hours (kWh) of storage. On the early
pre-launch cars, Mitsubishi claimed an 80 mile range,
but through the official 'NEDC' testing the figure is
published as an absurdly high 93 mile range. The
lower figure could be attainable in a very flat terrain
with little traffic and keeping to a modest speed, such
as we have practised in remarkably flat Denmark. A
range approaching the 93 mile mark has been achieved,
completely emptying the battery (not a good thing to do regularly)
in low speed city driving. In the UK, in typical use, we
suggest that a 65 mile usable range is a more accurate
guide. The more conservative EPA range figure from the
US of 62 miles is a more fair representation or a
combination of city and highway driving.
What could be of concern is that, if a new vehicle will just meet your needs, either for a commute or as a more general purpose vehicle, factor in a rough guide of a 2% decrease in range year-on-year as the lithium-ion battery capacity diminishes and that will be dipping under 60 miles after 5 or 6 years of average mileage. Our own empirical observations highlight that heavy traffic, heavy rain (and therefore drag-inducing surface water) and challenging terrain will rob you of a few miles over the entire range; an aggressive driving style or continuous use of the electrically driven heating or cooling considerably more.
It is worth mentioning that the generally accepted
industry norm for EV batteries is that they are
considered 'end of life' when they are down to 80% of
their nominal, published (new) capacity. When their
capacity has diminished to this level, it doesn't mean
that they are 'dead' and only suitable for recycling,
but consideration will/should be given to replacing the
battery pack and using the old one in a second life
application, such as a backup power supply for a
computer server installation which doesn't make such
arduous demands of the battery. We wait to see what
battery performance parameters are specified by the
manufacturers for their warranty, since 80% on this
vehicle would equate to, at best, a 56 mile range in our
estimation. Despite the 5 year warranty, this limitation
on the liability is worth bearing in mind.
Hot and cold
The use of air-con decimates range (by about 10%) particularly since it can easily be accidentally switched on (as we did) by turning the air flow control knob fully anticlockwise (activating the 'auto' setting.) As with ICE cars, but more critically, if you can park out of direct summer sunshine and 'vent' the car before driving, you will be more comfortable AND save valuable energy.
Unfortunately (unlike the Nissan LEAF) on the i-MiEV you don't have the option of 'pre-heating' or 'pre-cooling' the interior from mains electricity before setting out, meaning that you will be using some of the valuable battery capacity - especially if your vehicle is spending its nights outside in winter or parked in direct summer sun. There is now a standard heated drivers seat, which is useful if you will often be driving solo since it is far more efficient just to heat YOU than the entire cabin. In Japan, BOTH front seats are heated: here you will have to fire up the main heating if there's two or more on board.
Mitsubishi are following the model of selling the battery with the vehicle, rather than leasing the battery as favoured by Renault and ourselves. An advantage over other models such as the Nissan LEAF is that the long-term maintainability of the battery seems better: any individual failing module or cell (of which there are 88) could be economically replaced even outside of the 5 year / 62,500 mile warranty - not confusing this with the 'natural' aging from high mileages which will affect all the cells fairly evenly.
The inclusion of the battery with the vehicle raises the price to £23,990 (after the £5,000 UK government consumer incentive grant) We estimate that, compared to a conventional vehicle costing about £12,000, the i-MiEV can be cost-neutral over its life with mileages above about 11,500 per annum, even outside of Congestion Charging zones. In London, saving £10 per day on the Charge and further savings on parking, the car can pay for itself within a few years.
Mitsubishi i-MiEV comes with an 'on-board' 3 kiloWatt (3kW) charger which equates to a full charge taking about 7 hours (typically overnight, benefiting from cheaper and environmentally friendlier off-peak tariffs) or, equivalently, repleting about 12 miles' worth of charge per hour of daytime 'topping-up' or 'opportunity charging' whilst the car is sitting idle. The first of two charging inlets on the car is behind a conventional fuel filler flap on the driver's side rear corner, accessed by a release lever on the dashboard.
Mitsubishi (and Peugeot/Citroën) are supplying the cars with charging cable with a conventional mains plug. This should only be used at public charging stations and specially installed sockets but Mitsubishi are supplying a version which supplies the full 13Amps to the car, despite every other manufacturer realising that this is dangerous as indicated in our publication "Safety Issues concerning Electric Vehicle charging stations using conventional UK socket outlets." To use the full 3kW (13A) rate drivers should use a dedicated charging station in a public place or a 'wall box' at home. Vehicles should not be treated as electrical 'appliances' without additional precautions. ecodrive can supply alternative 10Amp charging cables and charging stations / wall boxes for safer charging.
The i-MiEV, following the Japanese convention and in common with the Nissan LEAF, also features the ability to Quick Charge from an off-board DC ChaDeMo charger, pushing high current energy directly into the battery through a similar, but larger, inlet to the 'normal' one on the opposite, passenger side, rear corner. The same connector (and same chargers) can be used on the LEAF and other forthcoming vehicles, despite differences in the specification of the different vehicles (different types of batteries, of different voltages or capacities) since the whole process is controlled by an exchange of information between car and charging station.
At the extreme this will take the car from empty to 80% charge (it has to slow it down then to avoid excessively heating the batteries) in as little as 30 minutes, from the chargers touted for public places in pilot areas. More typically, as a private driver, you would generally use one of these chargers in a convenient location for about 15 minutes, to extend your range by about 30-40 miles, on the rare day that your travels take you further from home or the combination of your errands and journeys have left you a little nervous about getting back home or to your next destination (with a 'conventional' charging opportunity) It is a pity that there is no intermediate charging solution between 3kW on-board and an expensive, and thus far rare, 50kW off-board charger.
The Mitsubishi i-MiEV is a
great contemporary compact EV, comfortably seating 4
adults, with more than adequate performance and simple
to drive. Anyone who drives (or has driven) an
automatic car can take to it quickly, making it ideal as
a pool car for local usage.
A variety of cosmetic options allow you to personalise
the car such as graphics, rubbing strips and leather
trim. Adding the expensive satellite navigation
option pushes the price towards that of Nissan LEAF
which has it (and more) as standard.
The standard '13 Amp' charging cable MUST be replaced
with a '10 Amp' version to maintain safety - and a
wallbox should be used for regular charging.
The Mitsubishi i-MiEV is available now from £23,990 including Plug In Car Grant (£5,000) and including battery.