Green Cars Buying Guide

If you do decide it makes sense to buy a greener car, the main options are an efficient "conventional" car, an electric hybrid, a fully electric model, or a car pre-converted to run on LPG. Electric cars are almost always the greenest, even if charged up by electricity produced mainly from coal and gas. They're still not widely available at the time of writing, though that is likely to change during 2010 and 2011. As for other types of cars, you can check the exact emissions of each vehicle you're considering online. Look for figures for CO2 and local air pollutants for practically every model from every manufacturer. The ETA site focuses on cars currently on the market and provides a handy overall environmental star-rating for each car, whereas the VCA site has data for second-hand as well as new models. 

Governments will often offer incentives or grants to help individuals buy low-carbon cars or convert their current vehicles to run on greener fuels. This, unfortunately, has come to an end, but buying a greener car still can be very attractive financially. The average car on sale at the time of writing will consume approximately $13,000 of fuel by the time it's done 100,000 miles - or maybe more if fuel prices keep rising as expected. Switching to a smaller, greener car could cut that figure by up to $6000. Furthermore, taxes are trending to tiers according to emissions, so while some SUVs cost $400 per year just to keep on the road, a car that emits less than lOOg of CO2 per km pays nothing at all. If you live in a city, you might also find that a low-emissions car qualifies you for a discounted or free residents parking permit. In London, electric cars and those powered by alternative fuels benefit from exemption from the congestion charge, too.

Is it more environmentally friendly to buy a new low-emissions car or to opt for a second-hand, perhaps less technologically advanced, model? Once again, there's no simple answer to this question. As we've seen, new cars cause emissions in production, but at the same time the best way to influence the overall market is by purchasing a new model.

If you do buy second-hand, the greenest choice of all is probably to pick up an old but reasonably efficient banger that not many other people are likely to want and to keep it running as long as you can. This way you'll be helping reduce the need for new cars while also making sure you use as little fuel as possible. This option won't suit everyone, of course, as it may be a headache in terms of maintenance.

If you're buying a second-hand car for only occasional, low-mileage use, then it arguably doesn't matter quite so much what you choose. Even if you pick a relatively high emissions model, you'll at least be stopping someone else buying it and driving it longer distances.