When Theresa May arrived in Downing Street two weeks ago to be confirmed as the new home secretary, the government’s team of drivers had their eyes glued to her car.
The shiny Jaguar XJ was fresh off the production line — the newest member of the ministerial fleet. With a fuel consumption of 40 miles per gallon, however, it did not quite suit the new government’s eco-friendly ethos.
Now Jaguar has a green alternative. The Limo Green is an electric XJ with a petrol engine to keep its batteries charged. It has the fuel economy of a small hatchback — 57mpg — and a carbon footprint close to that of a Toyota Prius.
It can run silently with zero emissions for up to 30 miles. Furthermore, it can accelerate as briskly as the big diesel saloons from Audi, BMW and Mercedes and cruise all day on a motorway at well beyond the legal limit.
The Sunday Times has followed this project from its inception and a few days ago I was among the first to test-drive Jaguar’s prototype.
Apart from the stickers on the sides indicating Jaguar’s partners in the project, it looks like any other XJ. It drives like one, too, though it is quieter. Limo Green’s rear wheels are driven by a 145kW electric motor fed from a lithium-ion battery pack under the boot floor.
A number of electric cars have been unveiled recently and are being readied for sale next year, when they will qualify for a £5,000 purchase incentive. The bulk, weight and expense of the lithium-ion batteries restrict the size and power of these pure electric cars. Nobody is offering an electric saloon the size of a Jaguar with the performance, long range and rear-seat comfort of a limousine and for good reason: the batteries needed would weigh nearly four tonnes.
The Limo Green is a new type of hybrid that Jaguar believes provides the answer. The wheels are always driven by the electric motor but the batteries are kept charged by a small petrol engine, which acts as a generator. This means there is no danger of being caught with a flat battery. Yet the car can also be plugged into the mains and charged overnight.
The forthcoming Vauxhall Ampera works on the same principle but will run on electricity alone until the batteries are depleted. Limo Green can go for 30 miles and up to 50mph as a pure electric but the petrol engine cuts in to boost the power whenever the driver demands vigorous acceleration or higher speed.
The car’s occupants scarcely notice when the engine starts, or when the two-speed transmission shifts into higher gear. From the driving seat, Limo Green is like a conventionally powered XJ but at low speed the loudest noise is the whoosh of tyres on asphalt.
At 1,750kg, Limo Green is only 50kg heavier than the Ampera but is a significantly bigger car. That is a tribute to Jaguar’s lightweight aluminium body and chassis construction that was pioneered with the XJ. Additional weight-saving measures, including special ceramic brakes and a carbon-fibre sub-frame, were contributed by Caparo, one of Jaguar’s partners in the Limo Green project.
The £4.2m two-year research programme, part-funded by the government’s Technology Strategy Board, also involves the Motor Industry Research Association, which has long experience of electric and hybrid vehicles, and Lotus Engineering, which has produced the light and compact 1.2-litre three-cylinder engine designed to run at a constant speed as the on-board generator.
Driving Limo Green, there seems no downside but then one is reminded that this prototype cost more than £1m. The cost is only one of several problems to be solved before an electric Jaguar appears in the showrooms.
The motor industry remains divided over the pace of electrification. The cost of lithium-ion battery packs keeps the price of small electric cars high and sales may stall after the initial wave of enthusiasm. Inevitably, a production Limo Green would be more expensive than the conventional XJ, which starts at £53,775.
Tata, owner of Jaguar Land Rover, has sanctioned a worldwide test involving up to 200 cars, starting in 2012. It will need to see positive results from this before it commits the £500m needed to move to full production.
Source: Business Times Online
