It has been a bumpy ride for carmakers in the push to reduce carbon dioxide emissions. Early hybrid technology, that enabled a car to be powered by both a petrol engine and a rechargeable battery, emasculated many marques. But as the engineering becomes more sophisticated, the odd-looking, stage-one hybrid models that resembled circus clowns' cars are being overtaken by models that aren't trying too hard to look different. Naysayers still question the extra weight the battery brings to the car, the length of time the vehicle can run before the battery needs recharging and the extra cost. Yet despite the challenges, just over the horizon looms the green sports car. It might not be speeding round the corner just yet, but a host of carmakers that produce the thirstiest of sports cars have now unveiled experimental green models scheduled to go into production in the next few years. And judging from the prototypes, it won't be necessary to forego style to be a green sports car enthusiast. Hong Kong is a burgeoning market for the high-end car market, and luxury models accounted for about 23 per cent of all passenger cars sold last year. But do drivers who can afford to pay HK$1 million or more for a status symbol on wheels really care about fuel economy? And do those who like to be seen in a flash sports car want to be caught plugging them into a mains socket? After all, a sports car is not bought for practical reasons. Benjamin Lam, chairman of the Porsche Club Hong Kong, says he would be keen to own a hybrid sports car. 'Hybrids are definitely the way of the future, once they become established,' he says. 'My wife has a hybrid Toyota [Prius] and it seems like it never runs out of petrol.' Lam, who drives a Porsche GT3, nevertheless admits that doubts still remain. A key concern among sports car lovers is the reliability of the cutting-edge technology in the hybrids, he says. A shortage of battery charging stations may also put some off but, Lam says: 'When they buy the car, they know the car needs to be recharged. Though of course, the more charging stations the better.' Ed Joyce, a businessman who drives a Porsche Boxster S, questions the feasibility of a green sports car and says it is just a marketing-led initiative. 'I think it is misguided to go down that route, but the car companies think that something has to be done,' he says. 'They want to be seen to be doing the right thing. The technology is not there yet with regard to the copper and lithium for the batteries.' Joyce also notes that hybrid cars can only run for about 150 kilometres on a battery before they need recharging. Carmakers are plugging away at the technology, and prototypes for green sports cars unveiled over the past year have looked promising on the surface. Among them, Ferrari unveiled its experimental Hy-Kers hybrid earlier this year, saying the concept was a marriage between green and Formula One technology. The prototype Hy-Ker was unveiled at the Geneva Motor Show in symbolic pea-green body paint. Based on the 599 GTB Fiorano, the carmaker says it has a high-voltage electric motor that produced more than 100 horsepower mounted at the back of a dual-clutch, seven-speed F1 transmission. There was 'seamless power coupling' between the electric motor and the V12 engine. No date has been given for the Hy-Ker's roll-out, but Ferrari says it will comply with strict European emissions rules without sacrificing performance. Porsche also unveiled its prototype hybrid 918 Spyder in Geneva and, taking note of the positive reception it received, followed up in July by announcing that the board had approved the car's production. The new Spyder, which Porsche says will pack more power than the motor show prototype, will use a 500 horsepower V8 petrol engine and electric motors that put out a total of 218 horsepower. Porsche offered more details on emissions cuts, saying carbon dioxide output would be capped at 70 grams per kilometre, corresponding to fuel consumption of three litres per 100 kilometres. It is expected to produce only 1,200 hybrid Spyders and has still not revealed when the car will ready. The catch: it will be priced at more than a whopping HK$4 million. When it comes to fuel economy, Lamborghini is the black sheep of the Italian car family, according to the Britain-based Environmental Transport Association, which voted the Lamborghini Murcielago the least green car of this year. But the carmaker has relented and is also working on hybrid technology. It says, however, that it's unlikely a green Lamborghini will roll out of the showrooms before 2015. Carmakers that do not produce thoroughbred racing cars, but are active in the field of motorsports, are also experimenting with hybrid technology. Audi says production of its A1 e-tron will start in 2012. The German carmaker says the e-tron will be a compact, premium-class, all-electric drive sports car with an urban range of 50 kilometres. An internal combustion engine recharges the battery when it's depleted, leading Audi to call it a 'zero-emissions car'. It says that the e-tron can sprint from zero to 100km/h in 10.2 seconds and has a top speed of more than 130km/h. Rumours have also circulated that BMW is developing a hybrid supercar called the M8. The buzz is that the M8 will have 507-horsepower five litre fuel engine paired with two electric engines, mounted at front and rear axles. It would be capable of sprinting from zero to 100km/h in an incredible 3.8 seconds and reaching a top speed of almost 300km/h. Dr Kay Segler, president of BMW's motorsports group, was adamant that the M division was not considering hybrid technology, although another sub-group of BMW was working towards pure electric-driven vehicles. 'When it comes to a battery, that increases the weight of a car,' Segler says. 'It may be as powerful but not as dynamic when it comes to handling ... so one has to be careful not to add any weight to the car. At the moment we are not having that technology in our [M-range] cars. It's really difficult to really have a pure sports car without a lot of added weight to generate a big pack of batteries.' The main reason that sports carmakers are turning green is not altruism. Developing hybrid technology does not come cheap and neither do the cars. The impetus among the European carmakers who are the leaders in thoroughbred sports cars, is the need to comply with European fuel-economy and emissions regulations that adhere to Kyoto Protocol guidelines aimed at reducing emissions. The Hong Kong government has also launched initiatives to wean drivers off fuel, mainly in response to deteriorating roadside air quality. Anyone buying what the Environmental Protection Department classifies as an 'environment-friendly' car enjoys a 30 per cent reduction off the first registration tax. The power companies have also been doing their bit to encourage the trend towards hybrid cars by introducing battery recharging stations. CLP Power announced last month it had installed its 21st multipoint charging station for electric vehicles in Kowloon and the New Territories. The stations are located in public car parks. Hongkong Electric, which supplies power to Hong Kong Island, has seven such stations. Both power suppliers are planning to expand the service. Joyce is not convinced that the move towards hybrids is a worthwhile endeavour. 'Even if the entire fleet of cars in the world went electric, it wouldn't make much difference to the environment because they're low down on the ladder of contributors to global warming. They will cost more. There is only so much lithium in the world. It's a rare metal, and lithium is the pinnacle of the technology. 'These cars have a 300 or 400 pound maximum battery to lug around, and with lithium, there's huge amounts of toxic materials,' says Joyce. A local chief executive of a public relations firm, who asked not to be named, also questioned the need for a hybrid sports car. After all, he says: 'Sports cars are like Harry Winston jewellery - people buy but seldom use them.' GREEN CARS: VITAL STATS Porsche 918 Spyder: a V8 combustion engine generating more than 500 horsepower is aided by electric motors on the front and rear axles that produce an overall 218 hp. The energy reservoir is a fluid-cooled lithium-ion battery positioned behind the passenger seat. Able to shoot from zero to 100km/h in 3.2 seconds, it has a top speed of 318km/h. Spews out 70 grams of CO2 per kilometre on fuel consumption of 3 litres/100 kilometres. Approved for production but no date for when the Spyder will appear in showrooms. Ferrari Hy-Ker: the experimental hybrid carries a V12 engine and a 40kg tri-phase, high-voltage electric motor coupled with a dual-clutch seven-speed Formula One transmission. The electric motor produces more than 100 hp with the goal of offsetting each added kilogram of weight by a gain of at least one hp. The electric drive unit acts as a generator when the driver brakes, using the kinetic energy to recharge the batteries. Ferrari gives no details on when the Hy-Ker will move into production (it's rumoured to be 2015) or how clean it will be, but says it will comply with future CO2 emissions standards. Lamborghini Gallardo: a hybrid version of a classic, the company says the car will be on the market in 2015 but has given very few details. Lamborghini says the car will have a small electric motor used solely to get the car moving at low speeds, after which power will switch to either a V10 or V12 engine for higher speeds. Audi A1 e-tron: comes with a 102 hp electric motor that Audi says can power the e-tron for 50 kilometres emission-free in city traffic. Once the battery is depleted, an internal combustion engine turns on to drive a 15kW generator. The car goes from zero to 100km/h in 10.2 seconds and has a top speed of more than 130km/h. A range extender that charges the battery allows the e-tron to cover longer distances. The extra range is 200 kilometres. The car will go into production in 2012.