Types of Green Cars
You rely on your car but you also care about the environment, so you face a dilemma - because every time you drive, your vehicle is pumping out harmful pollution. You need a car that is more eco-friendly. And the good news is that there are now several types of green car available including petrol, diesel, hybrid, electric and LPG models.
Petrol and diesel cars with internal combustion engines account for the majority of car sales and are likely to do so for many years to come. However, these engines are only around 20 per cent energy efficient so there is plenty of room for improvement. Manufacturers have been striving to make petrol and diesel cars greener through the use of cleaner fuels, catalytic converters and improved vehicle design. The cars have become more efficient and less polluting over the years thanks also to improved fuel management systems and advances in transmission technology. New developments, including start/stop systems, will further improve the situation. Start/stop combines engine, brake and battery management, stopping the engine when the car is at a standstill in traffic or at a red light. By 2015, one in five cars sold is expected to be equipped with such a system, cutting noise pollution as well as emissions when a car is stationary.
One of the least-polluting diesel cars of its generation is the Peugeot 207 which was launched in 2009. This Peugeot emits under 100g of carbon dioxide per kilometre - this is usually represented as ‘less than 100g/km CO2’ and is a good way of comparing how polluting, or otherwise, cars are. Any figure under 100g/km was considered to be low-carbon in the first decade of the 21st Century. The number of petrol and diesel cars achieving this status is increasing. The fuel consumption of petrol and diesel engines, which in 2010 was around 70 miles per gallon for some of the most efficient cars, is likely to be improved significantly in the coming years through downsizing, high-pressure fuel injection and advanced turbo-charging.
Meanwhile, hybrid cars, which use a combination of fuels, usually petrol and electricity (provided by charged batteries) or diesel and electricity, are becoming more popular among consumers looking for vehicles producing fewer emissions. Manufacturers are predicting that hybrid technology will soon see five-seater family cars capable of fuel economy of around 140 miles per gallon with carbon dioxide emissions of only 50g/km. Hybrids use internal combustion engines for cruising at higher speeds with the batteries providing extra power to the wheels through an electric motor when going uphill, for example, and during stop-start city driving. As well as using both at the same time, vehicles can also automatically switch between the two fuels. One of the most well-known hybrid cars in 2010 was the Toyota Prius.
All-electric cars are likely to make quite an impact, from a low starting point, in the second decade of the 21st Century. Most electric cars are powered by batteries which have been charged up from an electricity supply, though some cars being developed use on-board hydrogen fuel cells to create the electricity. Battery technology is moving forward and the current types are far more advanced than those of a few years ago. One of the big advantages of electric cars is that the cost of running them is significantly lower than that of petrol or diesel cars. This is helped by the fact that electric vehicles can be around 80 per cent fuel efficient. However, the relatively high initial purchase price of electric cars, concerns about their range and performance and the lack of recharging infrastructure have proved to be barriers to motorists buying these vehicles. Having said that, governments and other bodies can see the advantages of electric vehicles and are beginning to invest in networks of recharging points. In an attempt to encourage a bigger take-up of electric and hybrid vehicles, grants, tax incentives and various discounts are being offered.
The Reva electric car (known as the G-Wiz in the UK) shows the level of emissions that can be achieved: the car has zero emissions if charged using electricity from a renewable source and has 63g/km CO2 if charged with electricity from a conventional source.
Many petrol cars can be converted to run on LPG - liquid petroleum gas (also known as Autogas). This is generally a cheaper fuel to buy than petrol and is certainly less polluting. In the conversion process, a second independent LPG fuel system with its own tank is added to a car, making it a bi-fuel vehicle. Some manufacturers also produce new bi-fuel models.
Another greener fuel is biofuel which is created from renewable crops and plant oils and can be mixed with either petrol or diesel to power vehicles with internal combustion engines. Little or no modification is needed to use either bioethanol or biodiesel in existing cars. There are reservations over biofuels, however, because their production in some cases can result in destructive practices such as deforestation and intensive agriculture.
One final thought, when you are considering which type of green car you need, take into account the fact that smaller cars generally have less overall impact on the environment than bigger ones.
