cars
The OPAL guide to greener driving

It's great to jump in a car and visit friends, travel to work or go shopping, but cars are also a major source of atmospheric pollution.
The exhaust fumes that petrol and diesel-powered engines produce contain soot and a range of polluting gases including carbon monoxide, sulphur dioxide and nitrogen oxides - all of which can reduce the quality of the air we breathe. They also contain high concentrations of carbon dioxide, a ‘greenhouse gas’ that has been linked to climate warming.
Help reduce the impact of cars on our environment by following our simple tips for greener driving. Why not start today?
Three ways to drive greener
1. Drive less
Do you need to take the car? Try using public transport, or why not walk or cycle instead – you’ll save money and keep fit.
If you regularly drive the same route as friends, then consider car sharing.
2. Drive ‘green’
Sometimes we need to travel by car, but there are still ways to reduce the impact on the environment.
Follow these tips to drive more efficiently - you’ll burn less fuel, reduce emissions and save money.
- Ensure tyres are inflated to the correct pressure.
- Reduce the vehicle drag by removing roof and cycle racks when not in use.
- Accelerate and brake smoothly.
- Avoid over-revving the engine and use higher gears as early as possible.
3. Investigate cleaner fuel technologies
There are many cleaner alternatives to petrol and diesel-powered engines. Consider the following options when buying a new car.
Electric cars - are powered by a rechargeable battery, so do not produce exhaust fumes. The UK government is currently offering financial incentives to purchase electric cars.
Remember when considering electric that:
- electric cars have a limited range and need a place and time to be recharged
- batteries have a limited life and are expensive to replace
- much of the UK’s electricity is still produced from coal-fired power stations
Hybrid vehicles - are powered by both a petrol engine and a battery, which recharges as you drive. They are more fuel-efficient and emit less pollution than a standard engine, and do not need to be recharged like an electric vehicle.
Gas-powered vehicles - use gases such as Liquid Petroleum Gas (LPG). This fuel produces less soot and waste gases like nitrogen oxides, but still produces significant amounts of carbon dioxide. Bio-methane made from waste products is another fuel in development.
Biodiesel and bioethanol - are both fuels that can be produced sustainably. Biodiesel can be made from old cooking oil and specially grown plant crops, and bioethanol from fermented plant material. Existing engines can already cope with a careful blend of petrol and bioethanol or diesel and biodiesel.
Although biodiesel can be produced sustainably, it still produces polluting gases when burnt.
Fuel cell vehicles - use hydrogen to create electricity and power an onboard motor. The only emission is water (steam). However, producing hydrogen does create pollutants, unless renewable sources are used. This technology is expected to become widely available within the next 10 years.
Interested in finding out more?
Energy Saving Trust: www.energysavingtrust.org.uk/travel
Carbon Trust: www.carbontrust.co.uk
The AA - Eco-Driving Advice: www.theaa.com/motoring_advice /fuels-and-environment/drive-smart.html
Low Carbon Vehicle Partnership: www.lowcvp.org.uk
Biomethane as a fuel: www.ngvaeurope.eu
Join in the OPAL air survey

Investigate lichens on trees and find out about local air pollution.
Explore existing air pollution data
What do we already know about air pollution? What are the causes and effects of air pollutants?
Got a question about climate change?
Submit your question online and the Met Office will try and answer it for you.
Test your climate change knowledge
How much do you know about climate change? Take our online quiz to find out.
South East - join in nature activities and air pollution research
Discover your local environment with OPAL

Take part in an OPAL survey
Learn more about soils, water, lichens and climate, and contribute to valuable research with an OPAL survey.
Join in an OPAL event or activity
Get in touch to find out what nature and wildlife activities you can get involved in.
Tailored talks and events for your group or school
We can organise an event or talk specifically for your group. If you are interested, contact opalsoutheast@imperial.ac.uk.
Help us research the effects of car pollution
South-East England has some of the busiest roads in the country, with 5.2 million vehicles burning 6.1 million tonnes of fuel every year.
We need your help to explore the relationship between vehicle pollution and the environmental quality of our green spaces.
How do roads affect plants?
Help us investigate how roads are affecting heathland plants.
Download our heathland plant guide and recording sheet to get started.
Other downloads
Contact us
opalsoutheast@imperial.ac.uk
OPAL South East is led by Imperial College
See photos from previous OPAL events.