In a written parliamentary answer on the quantity of carbon dioxide produced by vehicles, junior transport minister Glenda Jackson said emissions from cars depended on a number of factors, including fuel and engine size. But, importantly, she added it also had to take into account driving conditions, driving behaviour and the maintenance of the vehicle.
The Government is trying to incentivise 'cleaner smaller cars', by cutting their excise duty by £50, while discouraging less environmentally-friendly cars by increasing their VED. This will have to be implemented according to information already held at the Driver and Vehicle Licensing Agency, and that is where the problem lies, because the DVLA only records a vehicle's date of registration, engine size and fuel type - an insufficient basis for any judgement on what constitutes 'cleaner and smaller'.
Department of Environment, Transport and the Regions' own figures have shown that it would be unfair to base VED on engine size. Small cars are not always either the most fuel-efficient or environmentally friendly in terms of carbon dioxide emissions.