Honda Civic knocked off top spot
It’s taken a long time to knock the natural gas version of the ever-popular Honda Civic off top spot – it has been ranked the greenest car for the past eight years by the American Council for an Energy-efficient Economy – but Mitsubishi’s i-MiEV has finally managed it.
Electric Vs Hybrid
The all-electric Mitsubishi I-Miev was awarded the highest ever score since the US rankings began in 1998, even though the Honda Civic natural gas has been improved, offering even better fuel efficiency this year. It tied in second place for 2012 alongside another Japanese-built all-electric vehicle, the Nissan Leaf. This is surely the latest sign that electric vehicles can cut it when competing against hybrids and natural gas competitors.
The survey calculates each vehicle’s green score based on a number of key variables including unhealthy exhaust emissions, emissions of gases that contribute to climate change and fuel consumption. The Mitsubishi i-MiEV came in first, despite the emissions generated from the electricity required to recharge its battery.
New Titanate Oxide battery in I-Miev
The original vehicle used a 16-kilowatt-hour lithium-ion pack with 88 cells in total, which is placed under the floor. The battery was jointly developed by Mitsubishi and partner company GS Yuasa. However, the Japanese automaker upgraded this technology last year with the introduction of a lithium titanate oxide SCiB battery, developed for the latest version of the i-MiEV and the minicab MiEV. Made by Toshiba, it is claimed that this new battery pack is capable of withstanding about two and a half times more charge-discharge cycles compared to an average lithium-ion battery.
Recharging time slashed
Another feature of this technology is that it uses the Japanese-developed CHAdeMO quick-charging method, introduced in 2010 by Mitsubishi, alongside Nissan, Fuji Heavy Industries and the Tokyo Electric Power Company. The great advantage is that recharging times are slashed significantly, taking just 15 minutes to charge the battery to 80 per cent of its capacity, 10 minutes to 50 per cent and five minutes to 25 per cent. In other words, the recharging times for the i-MiEV are only a bit longer than the time it takes to refuel a normal petrol and diesel engine, a major improvement on the half-an-hour or so many electric vehicles require, and a sign that these major disadvantages are slowly being addressed.
Longer Driving Range
These SCiB batteries crucially also offer a far longer driving range than the lithium-ion equivalents that have been the standard in the industry up until now. They typically squeeze out about another 70 per cent of distance per charge. There is also the option of installing a far smaller battery which offers the same range, so this new technology adds a certain degree of flexibility too. Another nifty feature of the i-MiEV is that it can be connected to the home to power domestic electrical appliances in the event of an outage, an addition that was made in the wake of last year’s earthquake and tsunami in Japan. Electric technology has come a long way and is going in all sorts of directions, and this latest award in the US shows it’s also becoming commercially viable.