Until recently, the internal combustion engine was the main power unit readily available to car buyers. Petrol and diesel-powered cars have been around for decades and have become increasingly sophisticated, delivering ever-better on-road performance and improved fuel economy. From the 1990s, the diesel engine in particular became increasingly popular, with better fuel economy than petrol and lower carbon dioxide emissions. In recent years, some exhaust emissions control issues of diesel engines have become apparent; some cities are banning, or proposing to ban, such vehicles from their centres and there has been a sharp drop in sales. Furthermore, the reduction of the use of fossil fuels is a central point of the agenda in the fight against climate change, which implies phasing-out fossil fuel vehicles completely.
Car manufacturers are looking to electric propulsion to reduce the emissions footprint of the fleet. Hybrid vehicles have been offered for several years and, by now, fully electric cars are becoming increasingly popular, which could drastically reduce emissions from transportation.
Today, many new models are offered with a range of power units: petrol, diesel, hybrid and, often, full electric. Petrol and diesel variants may be offered with a choice of power/torque outputs, often achieved by different engine mapping. Green NCAP aims to provide information about as many of these variants as possible but it is impossible for an independently-funded organisation to test all of them. The most popular vehicle types, across the range of powertrain types will be tested, to try to maximise the information available to consumers. In time, as more cars are added, the database will expand to provide a comprehensive resource to individual car-buyers and to fleet managers. To begin with, Green NCAP will look only at passenger cars and vans. The impact of goods and freight vehicles is recognised but is beyond the scope of the initiative, at least to begin with.
The most popular passenger vehicle types across the range of powertrain types are tested.
Green NCAP’s assessment now comprises two distinct aspects: the physical testing of cars, in the laboratory and on the road, to measure exhaust emissions and the energy needed for propulsion; and an analysis of the emissions and energy used in their production and use, along with that of the energy supply. This second aspect – known as Life-Cycle Assessments (LCA) – is recognised as the only way to fully assess the total impact a car has on the environment. Previously, an element of the LCA approach was applied only to the assessment of Greenhouse Gases, where the greenhouse emissions created during the upstream production of energy (liquid fuel or electricity, or both) was added to the emissions measured in Green NCAP’s tests. The rating now incorporates LCA into all aspects of the assessment – Clean Air, Energy Efficiency and Greenhouse Gases – and does so from production to final destruction (and recovery of materials where possible) of the vehicle. The methodology takes account of where in the world the vehicle has been produced, as some regions are still more reliant on fossil-fuels for their energy supply than others. A study performed for Green NCAP by A2MAC1, delivered the foundation for the estimation of the differences in vehicle production GHG emissions between different locations in the world.
Taken together, these aspects make Green NCAP’s ratings the most holistic and comprehensive assessment of cars’ sustainability, and the best tool for comparing their performance.
Life Cycle Assessment is now part of Green NCAP’s ratings, offering the most complete and holistic analysis of cars’ true environmental impact.
In the future, Green NCAP may also consider environmental factors such as noise – now proven to cause sleep disturbance, cardiovascular disease, elevated hormone levels, psychological problems and even premature death. So, the scope of the programme will continue to grow in the coming years and continue to be relevant for all types of powertrains.