Vehicles that burden the CO2 budget as little as possible – this has been an important goal since the Paris Climate Agreement. But what kind of drive is really sustainable? CO2 balance is not only affected by emissions during use, but also by the burden of production, infrastructure or disposal. For this reason, we examined life cycle analyses of various drivetrain technologies from 80 international studies, on behalf of the Research Association for Internal Combustion Engines (FVV).

We focused on three different drive technologies:

• vehicles with combustion engines, which in future can be filled up with an increasing proportion of e-fuels;
• battery electric vehicles, which could be charged with a greener mix of electricity in the future; and
• fuel cell vehicles that could be powered with hydrogen produced from renewable sources.

Opportunity lies in diversity

Our meta-analysis shows that the key to tomorrow's mobility is not a single technology, but rather its diversity - in the long term, all drivetrains could well enable CO2-free mobility. However, it also became clear that this diversity requires further research. Even if there is a large amount of data available, key information is still missing and single aspects of different technologies are not sufficiently captured yet. For example, many of the studies we have analysed don’t cover end-of-life emissions, others don’t cover need for infrastructure expansion etc.

A global challenge

Our study has caused a lasting impact and is quoted in and beyond the automotive industry - not least because of its policy implications. For an informed comparison of drivetrain technologies, cross-sectoral, global and unlimited life cycle analyses and objectives are needed.