See all Motoring AdviceIf you need to drive, but you’re also concerned about how cars can adversely affect the Earth’s wellbeing, then you might be thinking about reducing your carbon emissions, your nitrogen oxide output and any other tailpipe nasties that emerge from the back of internal-combustion-powered machines. So here are our top tips on how to buy a cleaner car, and how to drive cleaner too.
- Buy a smaller machine
Crossovers and SUVs are all the rage now, but taller (less aerodynamic), heavier vehicles are, plain and simple, heavier on fuel than equivalent cars with the same engine, and therefore harder on the environment to boot. Case in point: a 150hp 1.5-litre TSI Evo Volkswagen Golf emits 116g/km of CO2; a front-wheel-drive T-Roc fitted with exactly the same engine comes in at 151g/km. A Ford Focus Estate is going to be cleaner and greener than a Ford Kuga. Why have a Peugeot 2008, when a 208 will do much the same job? Our buying trends might be towards the lofty, but lower, more car-like vehicles will be better for the planet in the long run.
- Buy a petrol model
Whether you subscribe to the whole backlash towards diesel as a fuel post-2016 or not, the fact is that diesels emit more oxides of nitrogen (NOx) than petrol engines of the same sort of power and size. It’s why we now have a sliding scale NOx tax on new cars and used imports, which runs to a colossal €4,850 ceiling on diesels. On petrol cars? The same NOx tax is capped at a mere €600. Furthermore, modern turbocharged petrol engines are normally nearly as efficient as decent turbodiesels, so the fuel economy gains of going with diesel are not as clear-cut as they used to be.
- Buy a hybrid
If you want to cut your CO2 and NOx emissions even further, try a hybrid vehicle. You could start with a Mild Hybrid Electric Vehicle (MHEV), such as an Audi or the new Ford Puma, which’ll cut your tailpipe outputs by a significant percentage without requiring much in the way of ownership compromise (no charging etc). Step it up another level to the parallel hybrids (HEVs), like a Toyota Prius or similar, and your exhaust nasties will be further reduced. Go the whole hog and opt for a Plug-in Hybrid Electric vehicle (PHEV), and your official CO2 output can drop to as low as sub-50g/km, with NOx emissions reduced accordingly. Just remember that real-world CO2 output from a car increases in line with actual fuel consumption, so, if you’re using more fuel than the manufacturer’s official number, you’re also emitting more CO2. On longer journeys, diesel cars tend to be more economical, hence emitting less CO2.
- Buy an electric or a hydrogen fuel-cell vehicle (FCEV)
If you really want to reduce your tailpipe emissions, get rid of the internal combustion engine. Electric vehicles and also the much rarer hydrogen FCEVs emit nothing at all, save for water vapour from the FCEV, and so are the future of motoring. Albeit, they’re not the most inexpensive cars and there is no public hydrogen filling stations as yet. Fully electric is a more realistic option, though it’s worth bearing in mind that a massive percentage of Ireland’s electricity generation still uses fossil fuels…
- Drive smoothly, drive slowly, drive for long distances
The quoted CO2 and NOx figures that are appended to modern cars from manufacturers are measured during standardised tests as a way to compare one with another, but they don’t always translate to the real world. When the car is cold and going through its warm-up cycle, it will emit more from its exhaust because it is not running at its most efficient. When the car is moving in stop-start traffic in heavily congested urban areas, it will be burning through more fuel and therefore producing more pollutants. If you enjoy driving really fast on open roads, revving the engine right out to the redline and testing the handling to the limits, you will not be getting anything like the best fuel economy and emissions figures from the vehicle whatsoever.
- Adhere to other fuel-saving tips
Driving efficiently is the key to driving in the greenest possible fashion. Have a look at our guide on fuel economy tips and, beyond the already-mentioned need to be smooth and steady, try not to drive with under- or over-inflated tyres, empty roof racks, a boot full of junk, lots of electrical drains on the alternator, or even a full tank of fuel (half-a-tank weighs less and hence makes the car more economical). Any vehicle in poor condition is going to be polluting the planet unnecessarily, while – if you can – try and avoid driving at the busiest times of day on the most popular routes, or even look into car-sharing with colleagues; if you’re constantly driving to work with four empty seats in your vehicle, and you know that Dave from Accounts and Sarah from HR both work at the same place as you, on the same shifts, and they live near you or on the way to the office, then why not take it in turns to all travel in together in each other’s car from time to time?