We score cars on three main criteria.
1. Lifecycle carbon emissions
A lifecycle analysis (LCA) is the gold standard for measuring a car’s carbon emissions in its manufacture, use and disposal. At present, only a few carmakers carry out LCAs for the cars we cover. And even they don't all use the same international standard, making direct comparisons difficult.
In the absence of an LCA, we use the weight of a car as a proxy for its emissions in the manufacturing phase. (In other words, the heavier the EV, the higher the carbon emissions related to its manufacture are likely to be.)
Our proxy for the carbon emissions for the use phase of an EV’s lifespan is its efficiency—that is, its energy consumption per kilometre of driving.
The end-of-life phase is an immature and fast-evolving space with a number of complex dimensions, and there are not yet enough reliable data to separate EV carmakers from each other. Instead, we award points to any carmaker actively involved in a battery recycling program in Australia or elsewhere.
2. Sustainable technologies
Carbon emissions are not the only form of pollution or other environmental impacts caused by cars. This category includes a range of technological choices carmakers have made which can decrease or increase a car’s other environmental impacts.
3. Policy positions
Some car manufacturers have been enthusiastically championing the cause of electric cars. Others have either been quiet or have actively tried to undermine the speed of the transition in order to prolong the profitability of their fossil burners. These stances influence government and public perceptions so are necessary to identify and if necessary call out.
Scoring and weighting
After choosing the scoring criteria, we need to weight their relative importance. For this first version we have weighted 50 per cent of the total score to the lifecycle assessment or its proxies (#1 above), and 25 percent each to the other two categories. A summary table is below.
We used the forthcoming US-made Aptera Launch Edition as our benchmark. This radical three wheeler features a very low drag coefficient and enough on-board solar generation capacity to theoretically power itself for everyday trips if parked for long enough in the sun. It is due to go into production later in 2023, and scores 87.5 out of 100 points. There are no plans to introduce it into Australia yet. It is useful as an example of what can be achieved when environmental impacts and energy efficiency are primary design and manufacturing criteria.
To read more, download the full report (pdf - 2.4Mb)