Gavin Green’s new car taxes to replace our CO2 obsession

Published: 22 April 2011 Updated: 26 January 2015

The average CO2 emissions of cars sold in the UK have been cut by 12.5% over the past three years. So cars are clearly getting cleaner.

High fuel prices have clearly paid their part, as have CO2-based car taxation. Yet the system remains flawed.

Not least because the ‘official government’ fuel figures, on which the taxation is based, are so often a joke. A hybrid Prius carries zero road tax and is London congestion charge exempt. This is because it supposedly does 72.4 mpg (89g/km). Yet I don’t know anyone who gets anywhere near that figure in day-to-day use. In the real world, my Peugeot 107 – which does not qualify for zero road tax and is not congestion charge exempt – is generally more economical. I know this because I have driven many Priuses and have many friends who own them. Equally, there are plenty of small diesels that are penalised in car taxation and yet do brilliantly in ‘real world’ economy.

The ‘official’ figures are highly misleading. They promise parsimony that is mere pretence. Buyers have every reason to be disillusioned, when first they visit the pumps.

A much simpler formula for tax

I have a much simpler formula for road tax and company car tax, and it is much greener. In my view, the high price of fuel and forthcoming EU targets on CO2 reduction are quite enough to encourage us to buy fuel-efficient cars. Besides, the only ‘fair’ tax on vehicle CO2 – although you can certainly argue that it’s too high – is the duty on fuel. This directly taxes our fuel use and thus directly taxes our CO2 output. This should clearly remain although, I would argue, at a lower level.

Road tax and company car tax, on the other hand, should be based on a simple formula that takes into account a car’s total greenness. Namely, weight. The heavier the car, the more you pay. This way, you don’t need a strange test to determine the ‘official’ fuel consumption, either. Weight is altogether easier and less subjective to measure.

Why a car’s weight is a great differentiator

Weight has a very good correlation with total carbon footprint. It is a key factor in fuel consumption. Heavier cars generally consume more petrol or diesel. But weight also reflects all the other green issues that CO2 tax bands ignore.

The heavier the car, the more materials it consumes. So all that iron and aluminium being mined, and plastic being produced, and their associated transportation costs from source to factory, are taken into account. Bigger cars take more energy to make, and thus produce more carbon. They have more components, which take more energy to make and to transport. Heavier cars take more energy to ship from overseas factories. Heavier cars damage our roads more. They are more deadly if they strike pedestrians or cycles. Weight really is the root of all automotive evil.

And what about that old chestnut that the motor industry regularly trots out claiming that 60-85% (the figure varies from maker to maker) of a vehicle’s lifetime CO2 emissions come through use, and thus manufacturing/freight transport etc is barely relevant? It is disingenuous.

The great CO2 swindle

Makers typically measure only CO2 generated in their factory during manufacture. They do not take into account the energy used to mine, refine and transport the raw materials that go into making a new car. Or the CO2 produced by the many suppliers making the parts. Or the road and sea transport shipping cars. (The makers like to ignore these inconvenient truths because otherwise it may suggest that the best path to eco-responsible motoring is to keep your old car.)

The current CO2-based taxation takes none of these factors into account. My weight formula does.

By Gavin Green

Contributor-in-chief, former editor, anti-weight campaigner, voice of experience

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