Let’s cut to the chase: plug-in hybrids (PHEVs) are often hailed as the perfect compromise by car enthusiasts and politicians alike. A bit of electric power, a bit of petrol, and voilà, you’re eco-friendly without the fear of a dead battery in the middle of nowhere. But hold your horses, because a Dutch study has just poured a bucket of cold water over that green fantasy. According to the Netherlands’ Central Bureau of Statistics (CBS), these so-called environmentally friendly vehicles churn out more particulate matter than diesels. Yes, you heard that right: more than diesels, which have been vilified as the arch-enemies of clean air for years.
Let’s break this down, because it’s not small potatoes. Particulate matter—those tiny specks that sneak into your lungs and wreak havoc on your health—is a big deal. In 2023, Dutch road traffic spewed out about 3.6 million kilograms of this stuff into the air. Good news: that’s 16.3% less than a decade ago, thanks to cleaner engines and particulate filters. But here’s the kicker: per kilometre, plug-in hybrids emit an average of 0.027 grams of particulate matter, compared to 0.025 grams for diesels and a measly 0.017 grams for fully electric cars. Why? Because PHEVs are absolute heavyweights. With their batteries and combustion engines, they often weigh more than a small lorry. That extra heft leads to greater tyre wear, and—you guessed it—tyres are the real culprits when it comes to particulate matter.
Now, before you start thinking diesels are suddenly the holy grail, let’s keep things in perspective. Diesels are a dying breed in the Netherlands, and their overall contribution to particulate matter is minimal. Plus, particulate matter isn’t just about exhaust fumes. Tyres, brakes, and even the road surface itself play a massive role. Electric cars, which are often heavier too, aren’t immune to this, but they still take the eco-crown because they have no tailpipe emissions. And then there’s brake dust, which, according to research from the University of Southampton, might be even nastier than diesel emissions. Luckily, electric cars and hybrids often use regenerative braking, which cuts down on brake pad wear. But those tyres? They’re still a problem.
So why are plug-in hybrids such a mess? It’s all down to their dual nature. They’ve got a battery for short electric jaunts, but once that’s drained, they’re lugging around a heavy combustion engine that has to work harder to move all that weight. And if the driver forgets to plug in—which, let’s be honest, happens a lot—a PHEV ends up running mostly on petrol, with all the consequences that entails. The CBS points out that the higher weight of these cars causes extra tyre wear, and that’s exactly where the particulate matter comes from. Add to that the new Euro 6e-bis standard, which from 2025 will require heavier batteries for greater electric range, and you’ve got even chunkier cars producing even more particulates. Ironic, isn’t it?
Let’s take a step back. The Belgian government, in its infinite wisdom, wants to push plug-in hybrids as the ideal stepping stone to fully electric driving. Tax breaks, deductions, the works. But reading this study, you have to wonder if they’ve even seen the memo. It’s like telling a chain-smoker to switch to light cigarettes because they’re “healthier.” Meanwhile, the Flemish Environment Agency notes that emissions of PM2.5 (the tiniest, nastiest particulate matter) from road traffic dropped by 92% between 2005 and 2022. So yes, we’re making progress, but plug-in hybrids seem more like a sideways shuffle than a leap forward.
And then there’s the elephant in the room: tyres. We’ve long known that tyre wear is a major source of particulate matter. A 2020 study by Emissions Analytics even claimed that tyres could produce up to 1,850 times more particulate matter than the exhaust of modern cars. While those figures were later toned down (the test conditions were, let’s say, imaginative), the point stands: the heavier the car, the more the tyres wear. And plug-in hybrids, with their dual drivetrains, are proper heavyweights. Even electric cars, which are often heavier still, suffer from this issue, though they’ve got the edge with regenerative braking and no exhaust emissions.
So, what’s the deal? Should we all rush back to diesels? Hardly. Diesels might emit slightly less particulate matter per kilometre, but their impact on CO2 and nitrogen oxides is still a problem. And let’s not forget that fully electric cars, despite their weight, remain the cleanest option for particulate matter per kilometre. But it’s clear that plug-in hybrids aren’t the eco-miracles they’re made out to be. They’re a compromise, and like any compromise, you get the best of both worlds—and the worst.
The solution? Maybe it’s time to stop blindly championing half-measures and focus on real innovation. Lighter cars, better tyres, and more investment in public transport would be a good start. Until then, it’s up to car buyers to make smart choices. Want a plug-in hybrid? Fine, but make sure you actually use that battery. Otherwise, you’re just driving a petrol car with extra baggage.
For those itching to browse and pick a car that matches both their conscience and their driving style, check out our marketplace. At https://volty.be/nl/buy/cars/overview/, you’ll find a wide range of vehicles, from electric speedsters to frugal classics. Choose wisely, and don’t let those tyres wear out too fast!
