Purging the Sins of Car Emissions
In his latest monthly article on environmental issues, Professor Frank J. Convery, Chairperson of Comhar Sustainable Development Council, gives some tips on ‘ecodriving’ and on how to choose a fuel-efficient car to best meet your needs.
At Comhar Sustainable Development Council, we have spent a lot of time considering the environmental problems caused by cars and coming up with solutions to make this transport type more sustainable. The main environmental damage caused by cars is through fuel use and the emission of greenhouse gases, particulate matter, nitrogen oxides and hydrocarbons. In particular, greenhouse gas emissions from cars have risen hugely over the past decade: they have more than doubled since 1995.
While, ultimately, we need to get people out of cars and into alternative modes of transport, in rural areas, there is often no other way to get about. In these areas, transport by car now makes up more than 80 per cent of kilometres driven in Ireland. Until there are more alternatives, we may need to accept that – in the short term – car transport will continue to dominate. With this in mind, attention needs to be given to reducing the environmental impact of individual cars.
Changing the amount and the way we drive – ecodriving – is the most immediate and effective way of reducing our emissions and fuel consumption. This involves driving in a way that conserves fuel and costs nothing to the driver. It is now obligatory in many European countries to take ecodriving training as part of license-testing, something which Comhar believes should also be considered in Ireland. Upon completing this training, on average, drivers tend to reduce their fuel consumption by 25 per cent. In the longer term, this tends to drop to between five to 15 per cent.
Ecodriving involves changing habits to include the following:
• Checking tyre pressure before any long journeys, or at least every two weeks, to reduce wear and tear and conserve fuel.
• Taking any unnecessary excess baggage out of the car and removing roof racks and boxes when not in use to decrease fuel consumption.
• Driving more smoothly: accelerating and braking suddenly uses up to 30 per cent more fuel and again increases wear and tear.
• When accelerating, changing gear as soon as possible, ideally between 1500 and 2500 revs.
• Switching off or turning down the heating and air conditioning (but bear in mind that driving with the windows wide open increases drag and reduces efficiency).
While ecodriving can reduce fuel consumption, you can take a step further by changing to a more environmentally-friendly model of car. This is a very important decision, since the range of emissions produced by different cars is huge, even within one make and model. Bigger, heavier cars with powerful engines generally use more fuel than smaller cars with smaller engines. A fossil fuel-powered car that consumes more fuel produces more greenhouse gas emissions too. If you compare two like-for-like cars, a diesel car will always use less fuel and produce less CO2 emissions than a petrol car. However, diesel cars emit higher particulates and nitrogen oxide emissions than petrol cars, especially when stopping and starting in city traffic.
There is no one clear winner; it all depends on use. When choosing a new car it is therefore important to consider the kind of driving you do. For example, if the car is destined for long distances on the open road then a diesel car would be a good option for low fuel consumption; but, if city driving is intended, then a petrol hybrid would be better. The current crop of petrol hybrids tend to operate in electric mode when driving slowly (in traffic) and use the petrol engine when going faster. Therefore, they could have relatively higher fuel consumption in motorway driving. Car dealers are obliged to provide CO2 emissions and fuel consumption comparisons of all new vehicles. The Society of the Irish Motor Industry provides information on CO2 emissions from current vehicle models on their website, www.simi.ie.
Biofuels may be another low carbon option, but this depends on their production. Reports have shown that some are produced unsustainably and can create more greenhouse gas emissions than a fossil fuel. The biofuel source therefore needs to be checked for real net greenhouse gas reduction. A further consideration when purchasing a flexifuel vehicle (a vehicle that can run on biofuels or fossil fuel) is the location of the nearest biofuel station. If it is far away, the likelihood is that the car will mostly be driven using the fossil fuel mode, which may be less efficient than a normal fossil fuel engine.
The good news is that – as of 1st July 2008 – new car-purchasers will be rewarded for buying cars with lower CO2 emissions. Both VRT and motor tax will be levied according to the CO2 emissions of the car. Since motor tax is paid every year for the lifetime of the vehicle, it can be expected that the CO2 emissions rating of the car will also significantly affect the resale value of the car.
With fuel prices forecast to continue to rise; a carbon levy, and car taxes promoting lower CO2-emitting cars on the horizon, there has never been a better time for drivers to begin ecodriving, switch to a non-carbon based fuel or purchase a low CO2-emitting car.
Further ecodriving tips can be found at http://www.powerofone.ie/how/getting_around/index.html.