Autoblog UK

Audi has taken its green responsibilities literally and planted a 36,000-tree 'reservoir' near its Ingolstadt headquarters in Germany.

The trees are planted on the site of a forest that was destroyed in 2007 by 'bark beetles, drought and severe storms' and covers six hectares. Audi plans to set up several similar projects at other European locations, including one on a four hectare site near its manufacturing plant in Hungary.

The project is being created in conjunction with the Technical University of Munich, who will be studying how much CO2 the forest consumes.

Audi is keen to stress that the plantation of trees is not intended to replace its green efforts and will continue to look at ways to reduce the company's CO2 output.

1. What exactly is bioethanol?

Bioethanol (ethyl alcohol) is made from renewable resources by distillation after alcoholic fermentation, or by another similar biochemical method. In Germany, sugar beet or cereal crops such as wheat and oats are most commonly used to produce bioethanol. At present, no commercial manufacturing plants in Germany are producing bioethanol from lignocellulosic materials, e.g. straw or wood. Such processes are still at the pilot stage.

1. Can my car run on vegetable oil?

In theory, vegetable oil can be used in any diesel model. However, the engine would first need to be converted. Technical changes to the fuel injection pump and jets as well as to the fuel lines and combustion chamber should increase the fluidity and ignition quality of the vegetable oil. Basically, there are two possible engine conversions to consider: the single-tank and the dual-tank system. Both allow a car to run on diesel fuel, vegetable oil or a mixture of the two. Manufacturers are continually refining these systems to keep pace with developments in diesel technology. Which of the two is more suitable will depend primarily on your car's current fuel injection system. You will need to ask your car refitter directly whether your car engine is suitable for conversion. Sometimes, cars with fuel injection pumps made by particular manufactures are turned away, as certain systems are not suitable to be run indefinitely on vegetable oil. Depending on the extent of the conversion (for example, changes to the fuel injection pump, addition of a second fuel tank), a safety test equivalent to the MOT may be required. This should also be discussed in advance with the garage taking on the job. As yet, no manufacturer has approved an engine conversion that would allow a car to run on vegetable oil. It would therefore be very difficult to make a claim under the guarantee or in respect of material defects. You would also be unlikely to receive any compensatory gesture of goodwill in the event of engine damage.

1. What is autogas?

Autogas, also known as LPG (Liquefied Petroleum Gas), is a liquid mix of propane and butane stored under pressure, which is a by-product of oil and natural gas extraction and the refining of crude oil. Campers use LPG for heating, refrigerating and cooking. It should not be confused with natural gas (CNG – Compressed Natural Gas).

1. What exactly is natural gas?

Natural gas, along with oil and coal, is a combustible organic raw material. It is a mixture of approximately 85 percent methane plus around ten percent nitrogen dioxide and carbon dioxide. The remainder is made up of higher hydrocarbons such as ethane, propane and butane. Natural gas is available as two types: Compressed Natural Gas (CNG), which broadly maintains its natural state, and Liquefied Natural Gas (LNG), which becomes a liquid when cooled to -164 degrees Celsius. The great advantage of LNG is its significantly higher energy density per volume as, in a liquefied state, it is reduced to 1/600th of its initial volume. However, CNG is the more common, since compressed gas is currently easier to handle than gas in the form of an extremely cold liquid. Natural gas should not be confused with Liquefied Petroleum Gas (LPG) which retails under the name of Autogas.

1. What is biodiesel?

The fuel generally known as 'biodiesel' is actually rape methyl ester (RME), which is produced by the chemical treatment of rapeseed oil in a process called transesterification. This improves its fluidity and ignitability, thus making rape methyl ester very similar to conventional diesel fuel in its essential properties.

2. Can I run my car on biodiesel?

Only cars explicitly labelled by the manufacturer as suitable for biodiesel should be run on it. Otherwise, according to the German automobile club ADAC, there is a possibility of damage being caused, e.g. to the fuel-injection pump. It will also mean that you cannot claim under warranty or guarantee and that the manufacturer is unlikely to offer any compensatory gesture of goodwill. So before you fill up, do check your user manual to ensure your car is biodiesel compatible. If you have any doubts, it is safer to ask the manufacturer. In the current 'new car programme' (Euro 4 standard on exhaust gases), only the VW Golf V and Skoda Octavia II are approved for biodiesel – but only if they have been ordered with the special biodiesel option at an additional charge. Audi, BMW, Mercedes, Peugeot, Seat, Skoda, Volvo and VW have given biodiesel approval to some older models.

The Fisker Karma will be hitting the U.S. market later this year, shortly after which it should also be available in Europe. This four-door sports coupé is a good five metres long and will have hybrid drive, with two electric motors providing 204bhp to the rear axle. A four cylinder turbo engine is also on board to extend the range of the Fisker Karma to a maximum of around 310 miles. The limited top speed is regulated at 125mph. In sports mode, the car sprints from 0 - 60 in just six seconds.

We have heard a lot of talk from manufacturers about the powerplant of the future being the electric motor, but some of them have actually made a move. At the Geneva Motor Show, Mitsubishi presented their e-car, currently referred to as the 'i-MiEV'. In line with Mitsubishi's new brand strategy of increasing the proportion of 'green' vehicles within overall production, the i-MiEV should reach European showrooms in 2010. The spherical shape of this model looks familiar – but it's what goes on inside that matters. Here, Mitsubishi and Peugeot are working on a joint strategy for the European version. The car is being introduced into its Japanese home market this year. The four-seater is claimed to reach speeds of up to 130kph and have a range of 160 kilometres on a full battery. It takes seven hours to boost the battery from a domestic socket but should take only 25 minutes at a quick-charge station.

Wildly fluctuating fuel prices and the global downturn have persuaded motor manufacturers that they need to work harder on the production of thrifty models. At this year's Detroit Auto Show, there were plenty of new generation 'green' cars on display. Our fellow journalists at Autoblog Green have compiled their list of the Top Ten eco-models as seen in the photo gallery below:

The dramatic fluctuations in petrol prices over the last few years have compelled motor manufacturers to rethink their product palette. Customers started to demand fuel-thrifty vehicles, and that's what they got. Eco-cars with hybrid drivetrains are all the rage. Gone is the age of supersports cars and gas guzzlers. Or so you might think... The Detroit Auto Show still managed to parade ten vehicles where the process of filling the tank requires a deep pocket and/or a sense of humour.

Click on the link below to launch the Gas Guzzler Top Ten with a real burn-out.