By the time the auto industry finishes arguing about whether electrons or hydrogen will save the planet, the planet will have politely asked us to hurry up. That’s the inconvenient truth behind transport’s CO₂ problem: there are already about 250 million vehicles rolling around Europe, most of them burning fossil fuel, and they’re not going anywhere soon. So while the long-term shift to new powertrains grinds on, the fastest lever we can pull is a simpler one—change what goes into the tank.
That idea isn’t new. Bio-blended fuels have been around for years, but in the UK they’re still just that: blends. Regular petrol and diesel remain overwhelmingly fossil-based, with a splash of renewables mixed in for good behaviour. What is new is the growing push toward fuels that are 100 percent fossil-free and don’t require you to buy a new car—or even lift the bonnet.
They’re called “drop-in” fuels, and the name says it all. These are chemically engineered to behave just like the petrol or diesel they replace, meaning they won’t upset injectors, seals, or engine management systems. Increasingly, major carmakers are giving them the nod—sometimes across entire engine families, sometimes for vehicles built after a certain date.
Right now, the poster child of this movement is HVO100.
What Is HVO100, and Why Should You Care?
HVO stands for hydrogenated vegetable oil, though that undersells what it really is: a synthetic hydrocarbon diesel made from renewable raw materials. You’ll also hear it called renewable diesel, and unlike conventional biodiesel (the FAME-based stuff blended into UK pumps at around seven percent), HVO is chemically much closer to fossil diesel.
That matters. FAME biodiesel can cause compatibility issues in some engines, which is why it’s only used in small percentages. HVO100, by contrast, behaves so much like traditional diesel that, once approved by the manufacturer, it can be used neat—100 percent renewable, no blending required.
In other words, you fill up, drive away, and your car has no idea anything changed. The planet, however, very much does.
Carmakers Are Quietly Getting on Board
The momentum behind HVO100 is no longer theoretical. Stellantis last year fully validated its diesel engine range for HVO use, noting that many of its Euro 5 and Euro 6 engines were already compatible. BMW has gone even further, using HVO100 as a live demonstration of how quickly fleet emissions can be cut without waiting for everyone to switch to EVs.
The logic BMW put in front of fleet operators was refreshingly blunt: yes, electrification matters—but so does the fuel burned by the hundreds of millions of existing vehicles. Increase the proportion of renewable fuel in those tanks, and Europe’s CO₂ footprint drops almost immediately.
Since January, BMW has been putting its money where its filler cap is. Every diesel BMW built in Germany now leaves the factory with five to eight litres of HVO100 already in the tank, depending on model. The fuel comes from Neste MY, a Finnish producer whose HVO delivers up to a 90 percent reduction in CO₂ emissions on a well-to-wheel basis compared with fossil diesel.
“Well-to-wheel” is the key phrase there. It doesn’t just count what comes out of the tailpipe, but also the emissions created while sourcing, processing, refining, and transporting the fuel. In other words, it’s the full life-cycle carbon bill—and HVO100 still wipes the floor with conventional diesel.
BMW has approved all of its diesel passenger cars built from March 2020 onward for HVO100 use, with other manufacturers taking a similar date-based approach.
Not a Silver Bullet—but a Very Sharp One
Let’s be clear: HVO100 isn’t a magic wand that makes diesel guilt-free forever. But it is a remarkably effective stopgap—and maybe more than that. Unlike waiting for a full EV rollout, this is a solution that can be deployed right now, into the cars people already own, with almost no behavioural change.
No new charging infrastructure. No new engines. Just a cleaner liquid in the same old tank.
In a world obsessed with what’s coming next, HVO100 is a reminder that sometimes the fastest way forward is to fix what we already have. And for an industry desperate to cut carbon without hitting the brakes, that’s not just convenient—it might be essential.
Source: Autocar