First Oz drive: Electric i-MiEV coming, ready or not
BY IAN PORTER | 25th Mar 2009
MITSUBISHI’S little i-MiEV electric-powered city commuter doesn’t look like a load carrier, but it has been saddled with a considerable burden.
Mitsubishi claims to be the world leader in electric cars, and the i-MiEV is the car that has to deliver on the promise.
A first-drive opportunity this week did nothing to undermine that bullish claim.
But, when it comes to leadership, there is the little matter of 500 Mini Es running around in the US testing the market, but let’s not get picky.
The Mitsubishi i-MiEV is not that far behind, however, and will be ready to go into limited production in Japan around the middle of the year. Notably, it has also become the first electric vehicle certified for sale in Australia.
The Mitsubishi is ahead of the game in other aspects, such as being part-owner of a lithium-ion battery factory.
Mitsubishi also reckons the i-MiEV sets new standards in well-to-wheel energy use, emissions (or the lack of them) and low-cost operation.
The car Mitsubishi let us drive this week did not look like a kei car that had been chopped and changed into a development mule. It had all the appearance of a production-ready model with no apparent rough edges.
But Mitsubishi Motors Australia managing director Rob McEniry did see fit to issue a general warning to the assembled journalists: “Don’t drive it into the water, and don’t smash it, because it is the only one we have in Australia. It’s worth a hell of a lot of money. And my job.”The changes made to the original i car are virtually undetectable from the outside.
The original 660cc turbocharged four-cylinder petrol engine and gearbox behind the rear seat have been removed and replaced with an electric motor, inverter and charger, all under the standard-height floor of the load space behind the rear seat.
The petrol tank under the front seats has been removed and replaced with lithium-ion batteries.
While the i-MiEV has been created to cut emissions and reduce dependence on oil, this doesn’t mean the car will not be fun to drive.
In fact, Mitsubishi has produced something of a kei car GTI with this electric conversion.
While the electric motor produces 47kW, just like the petrol engine that was ripped out of the original i model kei car, the i-MiEV has a handy 180Nm of torque, almost double the original car’s 94Nm.
This is such a jump that the engine control unit has been set to limit the amount of torque delivered as the i-MiEV moves away from rest.
A quick glance at the torque “curve” shows that it is absolutely flat until around 2000rpm, after which it decays fairly rapidly. But it never falls below the torque curve of the petrol version.
This is great for performance. The i-MiEV gathers speed with a turbine-like lack of fuss and noise.
You can only imagine what the from-rest acceleration would be like when the after-market “tuners” learn how to take the restrictors off the torque delivery.
As with all electric cars, the acceleration is seamless and you tend to lose track of how fast you are going because there is no engine noise or changes in momentum caused by gear changes.
It just keeps pushing forward, and it is easy to find yourself on the wrong side of the speed limit without realising.
It’s not a tyre-burner, of course, with the torque restriction in place, but Mitsubishi reckons it takes 1.5 seconds off the original car’s 0-80km/h time.
Mitsubishi couldn’t give us a definitive time for the petrol car’s 0-80km/h time, but a graph in the presentation suggests it might take around 10.9 seconds.
We do know for sure the petrol car gets to 100km/h in 14.9 seconds, so it’s safe to assume the i-MiEV is at least 10 per cent faster than the original.
This is, in fact, pretty commendable, even with the huge torque increase, as the electric motor and batteries add 180kg to the weight, pushing the i-MiEV’s mass to 1080kg.
The performance achieved on the road depends on which “gear” the driver selects. There is a normal-looking transmission selector in the middle of the dashboard with three settings: Drive, Economy and Brake.
In Drive, the car can use all the available power when the car accelerates. Being an electric car, there is also the matter of regenerative braking, and in Drive this is set at what would be considered a normal setting.
When you back off, there is little retardation, just as in a petrol car in, say, fourth gear around town.
When the driver selects Economy, the control unit restricts the amount of power than can be used under acceleration, thereby conserving energy and allowing the i-MiEV to achieve its maximum cruising range of 160km.
Regenerative braking in Economy is the same as in Drive.
The Brake setting allows maximum power use but gives a higher level of regeneration under braking. The retardation when you back off is more noticeable, but nowhere near as strong as in the Subaru Stella prototype GoAuto drove before the Melbourne International Motor Show.
In the Stella, it was possible to tool around town in maximum regeneration mode and hardly use the brake pedal, as long as you had a reasonable chance to anticipate your next stop. In the i-MiEV, you needed to use the brake every time.
In an effort to keep the i-MiEV feeling like any normal car and make a driver’s adjustment easy, Mitsubishi has even engineered some automatic transmission “creep” into the system.
So, when you are stationary, you have to keep your foot on the brake, which is good for safety reasons as it means the brake lights are on and therefore the car is easier to see.
The degree of regeneration is clearly shown in the simple, three dial instrument panel.
There is one big dial with a pair of smaller dials looking like Mickey Mouse ears. In the centre of the large dial there is a digital speed readout and then there is a semi-circle above that which looks like a traditional analogue speedo. This is the energy readout.
At rest, the red needle points at about 10 o’clock on the dial. Below this is a blue zone and above is a green zone which turns into a grey zone as you get to the other end of the semi-circle.
When you accelerate, the red needle moves to the right, through the green zone and into the grey area if you accelerate hard.
When you lift off or brake, the needle swings back into the blue zone. In Drive and Economy, it goes only half way into the blue. When in Brake mode, the needle goes all the way to the end of the blue zone, to show you are achieving maximum regeneration.
The left-hand Mickey Mouse ear shows how much charge is left in the battery and the right-hand one contains the odometer and other signals. There is an array of warning lights below each ear.
The controls couldn’t be easier to use, and the steering is light and direct. The prototype added a classy feel with a leather steering wheel.
The cabin is the same as on the original i car. Under the swoopy, one-box design there is plenty of room for four adults.
Thanks to the typical tall set up for a kei car, headroom is ample and there is no chance of bumping your bonce on the way in or out.
Even the rear seat is comfortable for a typical ‘gaijin’ (westerner), with good legroom and no scraping of knees on the rear of the driver’s seat.
Mitsubishi is proud there has been no loss of cabin room during the conversion to electric drive, with all the batteries and drive unit accommodated where the old drivetrain used to be.
The lithium-ion cells are grouped into batteries of four cells each, and there are 22 of these batteries or modules altogether to give a total storage of 16kW/h.
Each cell is about the size of a videotape cassette, and this makes for easier assembly than, say, what happens at sportscar maker Tesla, where the company has to assemble 6800 AA-sized lithium-ion batteries to make its storage system.
The batteries are where Mitsubishi reckons it has one of its advantages over other manufacturers rushing to get into the electric vehicle business.
Mitsubishi Motors Corporation has partnered with Mitsubishi Corporation and leading battery maker GS Yuasa to build a lithium-ion battery factory, and this has already started production. Mitsubishi says this has given the company a strong position as it believes battery supply will be an issue in the near future.
It also puts Mitsubishi in a good position to meet the international standards on the longevity of batteries and electrical equipment. The company is confident its electric vehicles will meet the standard, which allows only 20 per cent deterioration in storage capacity of a battery or in the efficiency of an electric motor over 10 years before a battery or motor is considered unserviceable.
The i-MiEV is complete in almost all aspects, but there is one large oversight that Mitsubishi is currently rushing to remedy: it has not yet designed a fast-charge system for the i-MiEV, an area, for instance, where Subaru claims industry leadership.
The i-MiEV can only be recharged through a household electricity outlet via its six-metre cable. In Australia, with its 240-volt system, a full recharge would take seven hours overnight.
Mitsubishi has done a lot of work with the seven major electricity suppliers in Japan over the past three years and is currently working with Tokyo Electric (Tepco) to develop a fast-charge system.
The company expects this will allow an 80 per cent charge to be achieved in 30 minutes and a 50 per cent charge in 15 minutes. Mitsubishi is confident the fast-charge system will be ready to go when the i-MiEV goes into limited production later this year.
When production starts, Mitsubishi Australia will receive between four and six cars for the same sort of feasibility study that has already been started in some European countries and in New Zealand.
This will involve inviting government departments, other fleet owners and other stakeholders such as power suppliers to drive the i-MiEV and evaluate it for their purpose.
After that, it will all be down to Australia’s enthusiasm for electric vehicles and, that, in turn, will in all likelihood be determined by the international oil price.