Fuel Types

Petrol

Petrol has been the worlds most popular fuel used in cars for years. Petrol engines are thought of as quiet and smooth. A petrol enined car is also thought of as having good performance and responsiveness. Petrol engines emit approximately 10% more CO₂ than diesel. However petrol cars pump out less toxic emissions than diesel, e.g. Sulphur.

Diesel

Diesel engines have a better mpg/km/h than petrol engines, emitting less CO₂. Direct injection diesel engines yield the best fuel economy, diesels emit more particulates than petrol � but diesel engines with a particulate trap help prevent emissions of sooty particulates.

Diesel is generally more expensive than petrol, this is purely due to supply and demand. There are far more petrol producing refineries than of diesel. It is not possible to simply turn off the petrol and turn on diesel in a refinery due to different processes of production.

Unlike petrol engines, diesel engines have been seen as slow and noisy. Technology has seen some advances. Car manufacturers have designed diesel engines to be quiet, clean and with greater responsivness (i.e. Turbo Diesel).

LPG

In recent years, LPG (liquefied petroleum gas) has been a fuel option worldwide. LPG produces fewer emissions than both petrol and diesel but fuel economy suffers. It is possible to convert many existing cars to be fuelled by LPG. Some manufacturers have had new cars in their range that are dual fuel, (run primarily on LPG with petrol back up.) LPG, and natural gas in less ecomonical cars has been attractive due to its cheaper cost. Although there are some improvements in emissions over petrol and diesel, LPG is still derived from a fossil fuel and therefore still releases greenhouse gases into the atmosphere.

Battery-Electric cars

Electric cars use a battery and electric motor to power the vehicle, therefore have zero emissions (whilst in use). Battery capacity means the range between recharges is normally limited to about 50-70 miles, realistically making them only suitable for city-based users (watch out for the Fuel Cell).

They are recharged by plugging them into an electrical socket, some local government departments and large superstores/malls are now installing recharging points in car parks and on the streets (hopefully replacing the parking meter!) . Of course, there are only truly Zero CO₂ where recharging with electricity from renewable sources (windfarms) is guaranteed. Viable electric vehicles are still around the corner.

Hybrids

A Hybrid car is one which can run on two or more fuel sources. Hybrid technologies improve fuel efficiency and therefore provide considerable carbon emissions savings compared to a fossil fuel powered car. Models do cost more than conventional cars, however, running costs can be two-thirds of the equivalent fossil fuelled cars. Hybrids, bio-diesel and bio-ethanol vehicles are here now.

Petrol-Electric Hybrids

Petrol-electric hybrid cars run on a combination conventional petrol engine and electric motor powered by a battery pack. They work on the principle of an electric motor providing the power for low speeds (urban driving), and switch to petrol for higher speed driving. The batteries are recharged while driving and hybrids use regenerative braking, energy is transferred to the battery when braking. This improves energy efficiency.

Presently there are only a limited number of hybrid vehicle choices, four hybrids Toyota Prius, Honda Civic hybrid, Lexus RX400h and Lexus GS450h.

Only petrol electric hybrids are currently available, diesel-electric hybrids will achieve better fuel consumption. If you are lucky enough to live outside London, Hybrid cars exempted from the London Congestion Charge!!

Bio-diesel

Bio-diesel is an alternative fuel formulated exclusively for diesel engines; it is made from vegetable oil (or animal) fats.

Bio-diesel can be mixed with petroleum diesel in any percentage, from 1 to 99, which is represented by a number following a B. For example, B5 is 5 percent biodiesel with 95 percent petroleum.

The future is looking bright for bio-diesel. Not only is it easy to find and use, newer efficient diesel cars boast excellent fuel mileage. It�s one of the easiest alternative fuels to implement into your life: simply find a bio-fuel station and pump it into the tank of any diesel vehicle.

Bio-ethanol

Bioethanol is ethanol that is derived exclusively from the fermentation of plant starches. Though ethanol can be extracted as a by-product from a chemical reaction with ethylene and other petroleum products, these sources are not considered renewable, and thus the reason for the prefix ′bio′.

E85.has started to appear as an alternative on fuel pumps all around the world. This fuel is usually domestically produced from grain or biomass.

While pure ethanol is not sold as a stand-alone fuel, it is commonly mixed with gasoline as E85: 85 percent ethanol, 15 percent gasoline. In order to take advantage of it though, you′ll need a flex-fuel vehicle (FFV). These vehicles have to be specially designed with flex characteristics to apply the unique combustion process and tolerate the corrosiveness of the alcohol in E85