A study by two UK emissions experts has called for car taxation to be based on a combination of vehicle weight and mileage, arguing that such a system would be simpler, fairer, and more environmentally sound.
The proposal comes as countries worldwide grapple with how to tax cars in an era of mixed combustion and electric vehicles (EVs).
Nick Molden, CEO of Emissions Analytics, and Felix Leach, an Associate Professor at the University of Oxford, unveiled their findings in their new book Critical Mass: The One Thing You Need to Know About Green Cars, to be launched on Nov 25.
The book criticises current tax systems like the UK’s Vehicle Excise Duty (VED aka road tax), labelling them as “a ‘mishmash of incentives and penalties”.
Starting April 2025, the UK will include EVs in its VED system, ending their tax exemption. Buyers of new EVs will face a minimum first-year tax of £10 and a standard annual rate of £190 from the second year, both expected to rise with inflation.
Additionally, EVs costing over £40,000 will incur extra charges, and used EV and hybrid owners will also pay more. Molden (in striped shirt) and Leach argue that these changes risk adding confusion without effectively addressing environmental goals.
Their proposed system would tax vehicles based on their weight and annual mileage, which they identify as the two primary factors contributing to environmental impact.
Lighter, low-mileage cars would incur lower taxes, while heavier, high-mileage vehicles, including large SUVs, would face higher costs. For example, reducing a car’s weight by 150 kg or driving 1,000 fewer miles could save £100 annually under their model.
The authors pointed out that such a system would not only be easier for consumers to understand but also incentivise automakers to produce lighter, more efficient vehicles.
Molden said vehicle weight accounts for about three-quarters of a car’s environmental impact, making it a robust metric for policy and consumer guidance.
The idea is in line with global efforts to reform car taxation as governments face declining revenues from traditional fuel taxes and seek to promote greener vehicles.
Countries like France and Germany have explored weight-based taxation, while others, including the US, are experimenting with mileage-based road charges.
