The principle standards of a automobile’s eco-friendliness is mostly seen as the power it uses in its operation. Automobiles have primarily run on oil-primarily based gas within the form of petrol or diesel for over a century. However we at the moment are at the point the place demand for oil is rising so much, and reserves are declining, that oil is definitely running out. Oil costs have at all times been volatile and they react to speculation about events ranging from terrorism to hurricanes, however rising demand and diminishing reserves imply that overall, oil is simply going to carry on getting costlier. Nonetheless regardless of this, most vehicles at this time still rely on oil as their primary source of power; and oil is clearly a key contributor to carbon emissions, and climate change.


Petrol has been the most popular gas for vehicles in the UK for years; petrol engines are generally quiet and smooth, they are responsive and their performance is nice. Petrol is at the moment slightly cheaper than diesel. Petrol engines emit around 10% more carbon dioxide (CO2) than diesel. However petrol automobiles pump out much less toxic emissions than diesel. Sadly at the moment there is no such thing as a single supply of gasoline which can evaluate with petroleum by way of its instant bulk availability, energy density and (relative) cheapness.

Diesel engines are more economical than petrol engines, subsequently they emit less CO2. New ‘widespread rail’ diesels are approximately 10% more efficient than older diesels, and direct-injection diesel engines give the best gasoline financial system, diesels emit extra particulates than petrol – but diesel engines with a particulate lure assist stop emissions of sooty particulates – ie. the clouds of smoke that you’re going to expertise in the event you follow previous buses by towns. So diesel engines will typically provide you with more miles per gallon than their equivalent petrol fashions – simply look on the variations between comparable vehicles in our Inexperienced Automotive Information. Diesel is at present costlier to purchase than petrol, and the forecasts are that diesel prices will proceed to rise more steeply than petrol in the near future.

Diesel engines have all the time been seen as slow and noisy, nonetheless expertise has seen some outstanding advances in recent times; for instance Honda has developed their very own diesel engine that is designed to be quiet, refined, clear and with instantaneous response – preventing against all the previous stereotypes.


Over current years, LPG (liquefied petroleum gas) has been a viable fuel option in the UK. LPG produces fewer emissions than petrol and diesel however gas consumption is worse. It has been potential to convert many existing cars to run on LPG by after-market conversions, and a few manufacturers comparable to Vauxhall have had new vehicles of their range which can be twin-gasoline, which are designed to run totally on LPG with petrol back-up. There is a reasonable community of filling stations.

LPG, and natural fuel in heavier vehicles, has been a lovely proposition up to now primarily as a result of its cheaper cost, because it has enjoyed much less gasoline duty. Nevertheless there is no such thing as a assure that the Chancellor will maintain this sooner or later, and although there are some emissions improvements over petrol, LPG is still derived from a fossil gasoline and therefore still releases greenhouse gases into the atmosphere.


Some automobiles, normally heavier vans or trucks that usually run on diesel, but in addition automobiles such as the Volvo (V70 Bi-Fuel), can run on CNG (Compressed Natural Fuel), which once more results in lower CO2 emissions than customary petrol cars, however the fuel is just not as efficient as diesel. Finding CNG for refuelling could be a challenge.

Petrol-Electric Hybrids

Petrol-electric hybrid automobiles run on a mix of a standard petrol engine and an electric motor powered by an power storage machine akin to a battery pack. In easy terms they work on the principle that an electric motor offers the facility at low speeds equivalent to in urban driving, and they swap to petrol for driving at increased speeds. The batteries are recharged while driving and hybrids use regenerative braking, which means that power is put again into the battery when braking, which improves vitality effectivity.

Hybrid applied sciences enhance gasoline effectivity and subsequently provide appreciable gas savings compared with a traditional petrol vehicle – in addition to carbon emissions savings. While fashions might price greater than typical automobiles, working prices will be two-thirds that of equivalent petrol-fuelled autos.

Because of their lower CO2 emissions, hybrids additionally profit from diminished automobile excise responsibility and are handled favourably in Budgets. As well as they’re exempted from the London Congestion Charge.

Nonetheless in the mean time there are a restricted variety of hybrid vehicle decisions; there are at present simply 4 hybrids accessible within the UK; the Toyota Prius, Honda Civic hybrid, Lexus RX400h and Lexus GS450h. As they are still a comparatively new know-how, there aren’t many accessible second-hand and so they’re fairly costly.

Toyota’s first Prius (launched in Japan in 1997) did not promote in nice numbers, however a brand new mannequin has been introduced and that is now proving extra profitable. Although it appears to be like like a traditional automotive, it’s designed round vitality efficiency, and has many clever technological options that help gasoline consumption, including air conditioning and brakes powered by electricity quite than by sapping energy from the petrol engine. Lexus, part of Toyota, has launched a hybrid version of the RX300, identified because the RX400h. That is an SUV and because of its measurement, it nonetheless solely returns around 35mpg in comparison with the Prius’s sixty five.7mpg.

Although the official gasoline economy figures for automobiles such because the Toyota Prius at sixty five.7mpg sound great, they only really obtain most financial system benefits in constructed-up areas the place they primarily run on electric rather than petrol although the Prius can only drive for round a mile on battery energy before needing to revert to petrol; in actual-world motoring it appears difficult to attain the official figures. On a motorway run, a very good diesel is more likely to be extra economical. Nonetheless hybrids are still among the finest choices that the buyer has immediately to achieve better gasoline economic system, especially if a lot driving is completed in towns, together with the financial benefits resembling decrease tax and escaping London’s Congestion Cost.

Only petrol-electric hybrids are at the moment accessible; diesel-electric hybrids will obtain even better fuel consumption – be careful for these showing in the not-too distant future.

Battery-Electric cars

Electric vehicles use a battery and electric motor to energy the automobile, which means they haven’t any emissions at the point of use. As a result of capability of the battery, their range is often limited to about forty-60 miles between recharges, which implies they’re only actually appropriate for city-based users.

Electric vehicles can be recharged by plugging them into an existing electrical socket, and a few city councils are putting in electric recharging factors in automotive parks or on-road. Nonetheless, they are only truly ‘green’ if they are recharged with electricity from renewable sources corresponding to windfarms.

Electric vehicles usually are not topic to street tax and, as an added bonus for London drivers, they take pleasure in 100 per cent congestion charge discount. Drivers residing in areas the place they should pay for residential parking permits might also find that they get a discount on this price.

Electric cars are often thought to be the best non-polluters, however it’s not fairly that straightforward. They’re clearly good for lack of tailpipe emissions and are close to silent, however they need to hold rechargeable batteries. These batteries are probably not energy sources, they’re energy storers. This creates two points. Firstly they’re heavy and bulky with very low energy densities. Secondly, the unique supply of vitality, for recharging, needs to be questioned, because if it is not renewable, those autos will indirectly contribute to climate change. There may be a further disadvantage; if their batteries are lead or cadmium-based mostly, there’s a critical pollution problem if they are not correctly disposed of at the tip of their life.

The only electric automobile available in the UK in the mean time, although this is about to alter, is the G-Wiz, a small automotive for about-city use, claimed to be the greenest, most energy-efficient and cheapest automotive to run within the UK. It has two entrance seats plus two children size seats, which may be folded down for luggage. It’s in insurance coverage group 1, exempt from VED and the London Congestion Charge, and qualifies at no cost or discounted parking in some London areas. The G-Wiz is claimed to eat just one quarter of the vitality of the same-sized petrol automotive and costs around just £1.Sixty four a day to run, equivalent to round 600 miles per gallon.

Goingreen, the corporate behind the G-Wiz, ought to be commended on their efforts in bringing such a car to the market, and for some individuals, in the centre of London for example, it could present motoring with very low running prices. However it’s not sensible for everyone – its drawbacks embrace the truth that it needs a 6 hour recharge – you literally must plug it in! Petroleum Equipment – and its vary and velocity are limited. Apart from all that, its design is just not as cool, trendy and sophisticated as cars such as the Sensible or even the Toyota Aygo.

In summary, viable electric vehicles are still across the nook whereas hybrids, bio-diesel and bio-ethanol vehicles are right here now.



Biofuel has historically been in the form of biodiesel, presently out there in various sorts and qualities, primarily from vegetable oils, resembling from recycled cooking oils, and from crops reminiscent of rapeseed oil, each of which keep away from the carbon emissions of mineral diesel. However there isn’t any broad availability, unless in industrial portions, and it’s more commonly used to blend with normal diesel. There’s at the least one firm that’s at present building up a world-large biodiesel production and refining capacity but it is not prepared yet.

A variety of car manufacturers provide cars rated as completely compatible with biodiesel and even older fashions may be compatible. It is really useful that if your gasoline runs by means of rubber pipes they should be replaced with plastic equivalents. Biodiesel will take away dirt within the engine left by earlier use of petro-diesel and deposit it in the filters, therefore the filters need to be modified after the biodiesel has been used for some time. Biodiesel will work in most modern diesel engines (but not petrol!) but there are warranty implications – all automobiles must be checked for their compatibility for working on biodiesel.

D1 Oils is a British firm which recognises the rising demand for biodiesel and goals to become a world, sustainable, low value supplier of crude vegetable oil and biodiesel refiner. It has developed plantation rights and established refinery operations in several worldwide regions, making a supply chain from seed selection through to the sale of biodiesel to end customers. At present it has 4 operations centred within the UK, South Africa, Asia Pacific and India. There are additionally initiatives in Madagascar and Saudi Arabia. The primary plant source is the Jatropha tree which may grow in desert areas with a minimum requirement for water.

Grassolean is a US site where you can find info on starting your personal Biodiesel venture.

Green Fuels Ltd was formed to deliver affordable and sustainable biodiesel know-how to the UK and European market. They market decentralised plant for making biodiesel on a scale appropriate for house, business or locality. In addition they provide training.

Low-Affect Dwelling Initiative (LILI), a non-profit organisation helping to guard the environment by promoting sustainable alternatives. They run palms-on courses throughout the year including a number of on making your own biodiesel and there’s even one on vegetable oil as a motor fuel. They may also supply and deliver biodiesel to your private home.

Bio’petrol’ – Ethanol and Methanol Automobiles

Ethanol and Methanol are viable car fuels which are an alternate to petrol in inner combustion engines, giving considerable carbon emission benefits if the fuel is derived biologically. It’s cleaner inside the engine as well as outside. Vehicles often require adaptation to convert from petrol to ethanol if the focus exceeds 10% (E10) (manufacturers are usually conservative and warranties often state that not more than 5% ethanol ought to be added, however, most automobiles appear to run on E10). The required engine modifications to convert from petrol to ethanol are extra in depth than these to transform diesel to biodiesel. Several manufacturers are working to provide autos that will run on an 85% proportion (E85) and in the Americas and Canada, Flexible Gas Autos (FFVs) can run on E85 as well as gasoline (petrol). The place ethanol could be produced in abundance, notably Brazil, the fuel is used extensively. The alcohols even have potential for the uncooked supply in gasoline cells.

Recently, biofuels that can run with petrol have been introduced in the UK. The Saab BioPower and the Ford Focus Flexi-Gasoline are the only two new automobiles in the marketplace which can be designed to run on biofuel. For extra info see objects in our Information part.


Hydrogen fuel cells are seen as the fuel of the long run. Though they’re charged with very bulky hydrogen, it may be supplied in a liquid hydrocarbon compound and that means, theoretically, the density problem might be solved. To be local weather-friendly the compound should be renewable (bio(m)ethanol for example), not petroleum based mostly. One of the most important points of interest about hydrogen is that the one waste it produces is water.

Various manufacturers are developing prototype vehicles powered by hydrogen gas cells nevertheless they nonetheless demand a lot research and improvement to be commercially viable in automobiles and it is going to be quite a few years earlier than they’re widely available, together with the gasoline, in the UK.

Different applied sciences

Citroen has developed ‘Cease & Begin’ technology, presently used in two of its models. The conventional petrol engine shuts down if the car stops in traffic in normal driving. You continue to pay a premium over standard fashions for this technology, however they are cheaper than hybrids – but the fuel savings are usually not as great – the gas consumption doesn’t enhance significantly at all; like hybrids, they provide biggest benefit in city areas.