What is a Low Emission Vehicle (LEV)?
A low emission vehicle (LEV) emits less greenhouse gas than other similar vehicles. On this website, an LEV is any vehicle with a rated fuel consumption that does not exceed 7.0 litres per 100km and that is within 50% of the best in the class for greenhouse emissions. That means we show the lowest emitting vehicle in a class (say, Small Car), show other Small Cars whose emissions are within 50% of this one.
The kind of driving you do also affects your car’s level of greenhouse gas emissions. If you mostly drive in stop-start traffic – for example, in the city – a hybrid car might give you the lowest emissions. If you drive more on open roads, a modern turbo-diesel-engined vehicle may often be the best choice.
You may also be able to reduce emissions by using alternative fuels (such as LPG, biofuels).
Climate change is the greatest challenge to human civilisation for the foreseeable future. It is happening because humanity is releasing greenhouse gases (like CO2) at a rate far beyond what would occur naturally.
Transport is the second largest source of greenhouse gas emissions in Australia (stationary energy – the power we use in homes, businesses etc – is first). Transport is also the fastest growing source of emissions. Therefore, we urgently need to reduce greenhouse gas emissions in this area.
In choosing a low emission vehicle, you are making an important contribution to the fight against man-made climate change.
Hybrid Vehicles
A hybrid vehicle can give you significant greenhouse gas savings if you drive in stop-start driving conditions. This is because:
- the engine switches off when you stop (it doesn’t idle at traffic lights, for example)
- it has batteries which store and discharge electrical energy to help drive the vehicle
- it has an electrical motor which can either take over from or supplement its conventional internal combustion engine
- when you brake, the energy normally lost as heat is converted into electrical energy that is stored for later use. This is called regenerative braking.
Diesel Vehicles
Modern diesel engines are more efficient than petrol engines. They use up to 30% less fuel to produce the same amount of propulsion energy for the vehicle.
Diesel engines also produce harmful particulate matter (or PM). National vehicle emission standards require that these vehicles are better than they used to be, but they’re still not as clean as petrol engines. Many manufacturers are now fitting ‘Soot Filters’ or ‘Particulate Traps’ that can reduce these emissions by as much as 98%.
Diesel engines are generally best for highway driving. They’re most efficient at highway speeds, and the PM they produce is less harmful away from populated areas.
Alternative Fuel Vehicles
Liquid petroleum gas (or LPG) is the most widely used ‘alternative fuel’ in Australia. It is most efficient when it’s used in vehicles designed to run only on LPG. ‘Dual-fuel’ vehicles are less efficient, and some are a little more climate-friendly than petrol vehicles. Manufacturer fitted LPG equipment tends to be more efficient than conversions done after the car is bought.
Liquid petroleum gas (or LPG) is the most widely used ‘alternative fuel’ in Australia. It is most efficient when it’s used in vehicles designed to run only on LPG. ‘Dual-fuel’ vehicles are less efficient, and some are a little more climate-friendly than petrol vehicles. Manufacturer fitted LPG equipment tends to be more efficient than conversions done after the car is bought.
Using biofuels (such as ethanol and biodiesel) may reduce your car’s greenhouse gas emissions, but not necessarily. When we look at a fuel’s emissions, we calculate them from when the fuel is extracted (fossil fuels) or grown (biofuels) to when the fuel is used in the vehicle. A biofuel’s emissions depend on what was used to make it, how it was grown, and how much energy was needed to turn it into fuel. There is no way to know your biofuel’s total emissions when you are buying it, so you cannot be sure whether it is any better or worse than using another fuel.
The most widespread biofuel is ethanol, mostly sold as a 10% fraction of petrol (known as E10). Because it is so diluted, its greenhouse gas benefits - if any - tend to be very small. You are likely to get substantially greater reductions from using a hybrid or diesel.
Natural gas is plentiful in Australia. It comes compressed (CNG) or liquefied (LNG). It is not used much in transport. Although its greenhouse performance looks promising, it would need a massive investment in infrastructure to become a mainstream fuel.
