Green car buying guide 11 April 2008 Email this page Zoom Drivers are reaping the rewards of owning greener cars Cheaper tax discs and lower fuel bills But how do you spot a more efficient car and 'go green' in the first place? Tweet Our guide to greener buying explains all. We tell you what figures to look for, which cars to avoid and why the wrong choice could be costly. So, if you want to go green but don’t know how, we’re here to help. Greenhouse gas emissions Look at the car’s carbon dioxide (CO2) emissions, firstly. This figure gives a good indication of its green credentials and the lower the emissions in grams per kilometre (g/km CO2), the better. Find out your car's emissions here. Tax costs Road tax bands are heavily based on emissions, so a greener car is cheaper to tax. Many cars with small, frugal engines and low emissions are completely free to tax– meaning you pay no vehicle excise duty (VED) per year – and London congestion charge exempt, too. You can easily calculate your yearly car tax costs here.Fuel thirsty Another useful gauge of environmental friendliness is the car’s fuel consumption. It’s measured in miles per gallon (MPG), and cars with higher figures require refuelling less often. As a guide, Honda Insight (00-05) is very frugal and returns 83mpg. On the contrary, the Aston Martin DB7 Coupe (94-03) only manages 12mpg. Does your car measure up to our list? City car Find a green model Small hatchback Find a green model Small family car Find a green model Large family car Find a green model Small people carrier Find a green model Small 4x4 Find a green model Large 4x4 Find a green model Large people carrier Find a green model Jargon busting It's easy to be confused by motoring gobbledygook and dealerships can be daunting places as a result. That's why we've explained every puzzling term in our comprehensive glossary. So, don't worry if you don't know your hybrid from your Bluetec. You're not alone and we've got everything you need to know here. What if I don’t want to change cars? You can also cut costs and go green without buying a new car. Try our seven steps to greener motoring and find out how to save a packet. How green are you? Use the Parker's carbon footprint calculator to find out how green you and your car are. Calculate my carbon footprint More like this Ten greenest large 4x4s Ten greenest small family cars Ten greenest small cars Find your eco-warrior Carbon footprint