High emissions from hybrid cars

Drivers don't drive them they way they do in the test centre...
29 September 2020

Interview with 

Richard Black, Energy and Climate Intelligence Unit


A fuel gauge for a car


Hybrid cars are a significant slice of the automobile market. These vehicles claim to cut emissions, they’re incentivised by lower levels of tax, and are cited as a cornerstone to cut our carbon footprint. But new research from Transport and Environment, and Greenpeace, which followed 20,000 hybrid drivers, suggests that in real world usage, the emissions from hybrids are up to 2.5 times higher than the tests would have you to believe. Adam Murphy spoke to Richard Black, who’s the director of the Energy and Climate Intelligence Unit, who wasn’t involved in the study, about why there could be such a big gulf in the numbers…

Richard - The mismatch seems to be the testing. It doesn't take place in real world conditions. And so you can test them in a lab, where you can go out on a test drive and that's fine, but actually people don't always use cars as they do in a test condition. And I remember there was actually a study out a couple of years ago in the UK, which looked at the behaviour of company car, hybrid drivers. So people who've been given a company car that was a hybrid. And what they found was that a lot of those drivers weren't actually using the electric components of this at all. They were simply driving around using the petrol engine. And then of course, if you do this, your emissions are not going to be lower than they would be from just having the petrol, or engine itself. In fact, they might actually be higher because you're lugging around a big battery and so on, that you're not using it's just extra weight.

Adam - So what happens then, just for a bit of background, in those kinds of testing conditions that makes them so different from how the real world is?

Richard - Obviously the tests are done in an artificial situation. So you can go out on a test drive, whatever it might be, a 20 kilometre drive, but the driver knows why they're doing that drive. Sometimes the motor industry conducts tests in the laboratory, where the cars are mounted up on rollers and you fit a hose over the exhaust pipe, and you catch emissions there. But again, your driving behaviour will be changed by the fact that you know that you're in a test. What's also emerged a few years ago, when we had the so-called Dieselgate scandal, was that at times, the testing labs, they seem to have a slightly unhealthy relationship with some of the car companies. Now, I don't know if that's the case in this instance with the hybrid test, but you know, that's something that I see that is there in the history of motor manufacturing in Europe. So I think the main reason is though the behavioural one. We all know, for example, when we jump in a car, we know that the emissions are going to be highest when the engine's cold and we should sort of warm it up. We don't always do that because sometimes we're in a hurry. We don't always drive as the old driving instructors used to say, as though there's an eggshell between your right foot and the accelerator pedal to conserve gas, we accelerate sharply, we brake sharply, we do all these things. So that's why this real world data, I think is so interesting.

Adam - Would you be able to tell me a little about the new policy decisions?

Richard - The hybrids question matters in the context of a policy that the British government is expected to make in the next couple of months, which will be, basically, a ban on the sale of new petrol and diesel engine cars. It's going to set a date when that ban will come in. The date could be as early as 2030, it could be as late as 2035. And basically, the main reason from climate change terms for doing this, is because transport emissions in the UK haven't been falling. This is an obvious way to do it. It's an absolute no brainer. If you want to get to the net zero target, there are calculations also suggesting it would be good for UK GDP. There's a whole range of businesses that are behind this. So one of the questions is then, do include hybrids in this ban. And the government has been subject to intense lobbying from parts of the UK automotive industry, which make hybrids, and have invested heavily in hybrid drive trains, to say that hybrids should be allowed. But obviously what this new research does is to say, well, hang on a moment. If hybrids aren't actually much cleaner in real life, than normal petrol diesel cars, why would you allow them to be continued to be sold after this ban comes in? Why wouldn't you go straight for pure electric cars, and pure hydrogen powered cars as well? So that's why I think this finding coming as it is, is particularly important, because it does very much play into the logic of this decision that the UK government is expected to announce in the next couple of months or so.


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