BMW's Cooper diesel will pioneer Stop/Start engine technology in New Zealand, writes motoring editor Alastair Sloane
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Technology that carmakers say holds the key to more efficient motoring without the expense and weight of petrol-electric battery packs will go on sale in New Zealand within the next six months under the bonnet of the new diesel-powered Mini Cooper.
The BMW Group's two-door will be the first model in the country to use the Start/Stop system, which automatically switches off the engine to save fuel and cut exhaust emissions when the vehicle is stationary, like at traffic lights.
At the moment Start/Stop is available only in production cars with manual gearboxes, although it is being used in European trials in seven-speed automatics.
It switches off the engine when the clutch is disengaged below 3km/h and the gear lever is in neutral. It starts it when the clutch is re-engaged.
It works just like a petrol-electric hybrid, but without the hybrid's battery pack. Start/Stop is one of the reasons why hybrids do much better in city rather than highway driving.
It will be available in the new diesel Mini along with BMW's "Efficient Dynamics" technology, a package of lean-burn engine add-ons and equipment upgrades often referred to as mild hybrids.
Among them is Brake Energy Regeneration, which captures the energy used in braking and uses it to recharge the car's battery, instead of drawing on the engine. It is already in use on BMW models here.
Combining both technologies, says the company, cuts fuel consumption and CO2 exhaust emissions by between 8 and 15 per cent.
It says the Mini Cooper D is good for town-and-around fuel use of 3.9 litres/100km, or 72mpg. On the open road, it can get 3.5 litres/100km, or 80mpg.
BMW Group NZ managing director Mark Gilbert said that he expected Start/Stop to appear in the Mini Cooper D by early next year.
"It is part of the company's strategy to improve fuel economy without sacrificing performance," he said.
"We are achieving enormous improvements in fuel economy by working with technologies that are available today and without adding significantly to the retail cost of the vehicle.
"According to the International Energy Agency, the fuel economy of cars and lighter trucks can be doubled using existing technologies and at a reasonable cost.
"Compare a 1983 BMW 320 model with the equivalent 2008 version. Power has increased by 36 per cent, while fuel consumption has decreased by 36 per cent, and the exhaust emissions quality has improved by 95 per cent."
Gilbert said he expected Start/Stop and other fuel-saving technologies to be introduced into BMW vehicles in New Zealand over time.
Such packages are fuel-critical. The lean-burn engines in Efficient Dynamics work only with fuel with a maximum sulphur content of 10 parts per million.
The 50ppm of sulphur in New Zealand petrol is too high. There is talk that it will be cut but there is no timeline in place. Sulphur in diesel, however, will be reduced to 10ppm next year, when the Mini Cooper D appears. But New Zealanders won't be able to buy petrol Start/Stop vehicles until the fuel is cleaner.
German specialist Bosch developed Start/Stop for BMW. Bosch chairman Bernd Bohr says it is cheaper and more efficient than hybrid technology. He expects it to make up 20 per cent of the European market - one in five cars - by 2015.
Citroen is using it, Mercedes-Benz is about to introduce it on selected models and Fiat says it will be available right across its fleet within the next 18 months. Alfa Romeo and Lancia will get it too.
The advantage of Start/Stop is that it's relatively cheap to make, says Bosch, which developed a high-tech starter motor to manage the system.
Says Dr Volkmar Denner, of the Bosch board of management: "Incorporating Start/Stop requires no other change to the vehicle's drive train or the engine. The system delivers an excellent cost-benefit ratio, making it very attractive compared with alternative solutions.
"The number of engine starts the system has to make, in other words its service life, has been increased significantly for this application.
"In addition, the starter's improved-performance electric motor, low noise and stronger pinion-engaging mechanism ensure that the engine starts reliably, quickly and quietly.
"Despite the increased number of functions, the starter is compact and can be integrated into the vehicle just as easily and conveniently as other starter motors."
