Why official car CO2 emissions are a lie

Car CO2 Emissions - an even bigger lie than official economy figures

Motorists buy cars based on, and are taxed on, their CO2 emissions. But the CO2 emissions are as big a lie as the official economy figures.

We’ve banged on forever about official economy and emission figures and how misleading they are. But it’s worse than that – they’re a complete lie.

Did you think car makers had to submit their cars to official CO2 emission tests? Wrong. CO2 emissions are worked out purely on the basis of official economy figures. And we know how much of a lie they are.

Official economy figures are worked out by submitting cars to a rolling road test in a lab. That’s right, at no time do officials take a car on to real roads and see what it can do. Which means car makers can ‘Game’ the system really easily by mapping a car to achieve maximum economy, often to the detriment of real world performance and economy.

That’s bad enough, but where it gets really silly is when it comes to CO2 emissions – the stuff that actually dictates what our VED and BIK rates are. To calculate official CO2 all officials do is take the ‘official’ average mpg and use that to determine the ‘official’ CO2 emissions.

Try it for yourself – if you’ve got a diesel car just divide 7440 by the official combined mpg and that’s your official CO2 (for petrol use 6740). That’s how scientific it is.

It also means that when car makers spout the silly ‘official’ economy figures for hybrids and EVs they can simply extrapolate a similarly stupid CO2 figure using the same daft cod science.

We applaud What Car’s attempts to deliver real world economy figures with their new ‘True MPG’ campaign, but the real scandal is the CO2 emissions which are based on the same flawed mpg figures, and which dictate our tax liability.

It’s time to change the emissions and economy tests completely.

By Cars UK