Our testing has found that almost all modern diesel cars exceed official emissions limits when tested in real-world conditions. We even found some hybrids breaking the limits too. So how can we trust car emissions claims?
Consumer news in 2015 didn’t get much bigger than the Volkswagen (VW) emissions scandal. The ramifications were (and still are) huge – not just for VW and the owners of affected cars, but for the whole motor industry.
Our testing is different to the official testing procedure used. It still takes place in a lab, but we use more challenging and realistic driving cycles to provide more accurate figures.
So using our lab results on over 300 cars that we’ve tested since 2012, we did a deep dive on the data. And the results were interesting.
It’s not just VW – and not just diesels either
What we found is that it’s not just VW that have been pumping out some peculiar claims. We looked back over three years’ worth of data, across all manufacturers whose cars officially comply with modern emissions regulations, known as Euro 5 or Euro 6 depending on the age of the car.
What we found was an astonishing 95% of diesel cars exceeded oxides of nitrogen (NOx) limits in our testing. The worst offender emitted 15 times more NOx as its Euro 5 engine is permitted to.
And it’s not just diesel engined cars either. We found that one in ten petrol cars produced so much NOx that they too are breaking emission limits. Now, petrol cars do also produce NOx, but this is supposed to be in such small quantities that it’s of little significance and well under the limits set. The worst offender we found emitted 15 times more NOx as its Euro 5 engine is permitted to.
We also found two thirds of petrol cars are creating far more carbon monoxide (CO) in our tests than EU limits.
CO is different to carbon dioxide (CO2) – CO2 is harmful to the environment and your car tax is based on how much CO2 your car creates. CO on the other hand is much more harmful to human health and has no effect on car tax.
Worryingly, in our tests, two thirds of petrol cars put out more CO into the air than they’re allowed to. The worst created more than five times the amount of CO than the official limit. And it’s not just sporty or big cars that are to blame – several superminis with small capacity engines are among the top offenders. And some were so bad that they couldn’t even meet the early ‘Euro 1’ limits from 1993 – which are pretty lenient compared to modern standards.
To our surprise we also found some hybrid cars are also breaking emission laws. Testing revealed that some petrol-hybrid cars emit more CO than they’re allowed – in fact one petrol-hybrid was the 11th highest CO emitter we’ve found so far.
We’ve also identified a diesel-hybrid that produces more NOx than limits allow. And what makes this even worse is that there is no special lower limits that hybrids are held account to.
So what now?
We want you to be able to trust car makers’ fuel emission and efficiency claims. We need a stringent, independently audited test regime in the EU. It’s no coincidence that the VW scandal broke in the US, where such a test regime operates. The flawed European system allows carmakers to declare lab figures that rarely bear any relation to real-life emissions.
As a VW owner I’m currently awaiting the ‘fix’ to my car, as I’m sure thousands of you are. Last week we heard that VW has no plans to compensate VW owners in the UK, as they have in the US. But I’m curious to know whether this fix it will have any bearing on how my car performs, or on the pollution it produces in daily driving. VW has insisted that there will be no change to performance, but I’ll wait and see.
Since September, more than 78,000 people have backed our ‘Come Clean on Fuel Claims’ campaign. If you agree that more needs to be done to make car manufacturers come clean on emissions claims then back our campaign today. Also, tell us what you think about your car in our Car Survey.
So what do you think about these car emissions claims? Have you been affected at all?
*All Euro dates refer to new car registrations