How green is your older car?

Is it greener to buy a new, fuel-efficient car or run your current motor into the ground?

Car salesmen would have you believe that new is best, but older can be less environmentally-damaging overall as well as easier on your pocket. Most car cost calculators are skewed by depreciation; a factor that is significant in the first three years, but inconsequential where mainstream cars are concerned once they reach the age of ten.

Irrespective of the energy required to build a car in the first place, annual mileage plays a significant part in any comparison between old and new vehicles. Production date is important, too – since the introduction of the first Euro emission ratings in 1993, there has been a significant and rapid reduction in harmful exhaust gases.

While consumers are becoming better informed about car emissions, the environmental cost of car manufacture remains almost entirely overlooked. Although progress continues to be made by car manufacturers in terms of the amount of energy and water they use, and the amount of their waste that goes to landfill, these factors continue to have a significant impact on the lifetime environmental impact of cars.

According to the industry figures used in the Cleaner Vehicles Task Force’s first background paper ‘The environmental impacts of road vehicles in use: Air quality, climate change and noise pollution’ some 80–90% of a vehicle’s lifetime energy consumption takes place during its ‘in-use’ phase. However, this is contradicted by the research, ‘Life-cycle energy consumption and carbon dioxide emissions of world cars’ by Kimmo Klemola, D.Sc. (Chem. Eng) Laboratory of Industrial Chemistry, Department of Chemical Engineering, Lappeenranta University of Technology, Finland (14 February 2006), which comes to the conclusion that:

“The tank-to-wheel fuel consumption is only part of the story. Petroleum and fuel transport and production consume energy, as well as car manufacturing and scrapping and the maintenance and infrastructure. The total energy consumption of car use is on average 54.7% higher than the tank-to-wheel energy consumption alone.”

The greenest car is the one left at home in favour of cycling to work or walking to the shops.

Converting MPG to CO2

Motorists who drive cars that were first registered before 2001 are unlikely to be aware of how much CO₂ their vehicle emits.

A car’s V5 document (sometimes referred to as the logbook) details the amount of CO2 the vehicle emits per kilometre, but this is not the case for vehicles registered before 1st march 2001.

How do you know how much CO2 your car emits?

If you know a car’s mpg figure, you can use a simple calculation to work out its CO₂ g/km figure.

The calculation is simple, but you may find it helps to use a calculator.

Going for a second-hand car can be a green as well as financially-canny alternative buying new.

Cars lose up to half their value after three years, but at that age should still look and drive like new and remain reliable. New cars tend to be more reliable than second-hand cars, but their assembly, delivery and even marketing have consumed significant resources before you have driven them off the dealer’s forecourt.

It’s best to choose with a well-documented service history. It can make economic sense to spend more repairing a vehicle than its market value; reliability is the key.

Buy small, hire large

Buy as small as you can for your day-to-day needs. You may decide you need a big car because you have relatives that live over 400 miles away. If you only visit them twice a year, however, and most of your driving is done in a 50-mile radius a big car may be inefficient. By buying a smaller car for the majority of driving, and renting a bigger car for the long trips, you will save money.

Car clubs offer money-saving and green alternative to private car ownership, and some people simply have an informal arrangement with friends or neighbours,. If you drive less than 6,000 miles per year, it is claimed a car club could save you up to £3,500 a year. Many people don’t notice the true costs of running a car, but when you add up the cost of tax, MOT, fuel, servicing, repairs, depreciation and parking it is often more than you expect.

Petrol or diesel?

Neither engine type is truly green or sustainable – not least because oil reserves are essentially a finite non-renewable resource. There is a popular belief that due to their lower average CO₂ emissions, diesels are better for the planet. Diesel engines are generally more efficient at burning fuel and using the created power, they also warm up in half the distance of their petrol counterparts (the most critical period for vehicle emissions). As such they produce less carbon dioxide (CO₂), carbon monoxide (CO) and hydrocarbons (HC) than the equivalent petrol engine. Unfortunately it appears that it is people, particularly those in built-up areas, that are paying the price. Tens of thousands of deaths are caused by air pollution in Britain every year – those with respiratory problems are most at risk.

Diesels emit the bulk of emissions that endanger health, causing asthma, chronic bronchitis, heart disease and cancer, and such vehicles will, from 2020, have to meet the strict Euro 6 emissions rating. Most diesel cars have yet to meet Euro 6.

Car makers can now offer as an option a filter for diesel-engine cars that completely removes all trace of particulates form the exhaust. If most of your driving is in urban areas, ensure the car you buy meets the Euro 6 environmental rating.

An ethical company

The ETA has been rated ethical in Britain for the second year running by the Good Shopping Guide.

Beating household-name insurance companies such as John Lewis and the Co-op, the ETA earned an ethical company index score of 89.

The ETA was established in 1990 as an ethical provider of green, reliable travel services. Twenty seven years on, we continue to offer cycle insurance, travel insurance and breakdown cover while putting concern for the environment at the heart of all we do.