HVO stands for hydrotreated vegetable oil, a renewable diesel fuel made by processing plant oils or waste fats with hydrogen. Unlike traditional biodiesel, HVO is chemically almost identical to fossil diesel, which means it can replace conventional diesel in most engines without any modifications. It’s one of the fastest-growing alternative fuels in Europe and is gaining traction in North America as fleets look for lower-carbon options.
How HVO Is Made
The production process starts with a fat or oil feedstock, which is reacted with hydrogen at high temperatures in the presence of a catalyst. This strips out the oxygen molecules found in biological oils and saturates the carbon chains, producing a pure hydrocarbon fuel. The result is a liquid that behaves like petroleum diesel but comes from renewable sources.
The most common feedstocks are used cooking oils, animal fats (tallow), and vegetable oils like rapeseed or soybean oil. Waste-based feedstocks are increasingly preferred because they don’t compete with food production. Using virgin palm oil, for example, carries a much higher carbon footprint: life cycle emissions for palm-oil-based HVO can reach 0.748 kg CO₂ equivalent per kilogram of fuel produced, compared to far lower figures when used cooking oil and green hydrogen are used instead.
What Makes It Different From Biodiesel
HVO and traditional biodiesel (known as FAME, or fatty acid methyl ester) both come from biological fats, but they’re chemically very different fuels. FAME biodiesel contains oxygen in its molecular structure, which gives it about 7% less energy per liter than petroleum diesel. That oxygen also makes FAME prone to oxidation during storage, which can corrode tanks and fuel lines over time. FAME is also more susceptible to microbial contamination, sometimes called “diesel bug,” when storage conditions aren’t well managed.
HVO has none of these problems. Its molecular makeup is roughly 90% branched paraffins and 10% straight-chain paraffins, all in a narrow carbon range of C14 to C18. There’s no oxygen, no aromatics, and no sulfur. By contrast, conventional ultra-low sulfur diesel contains a complex mix of hydrocarbon types, including over 50% cycloparaffins and small amounts of aromatic compounds. HVO’s simpler, cleaner chemistry is what gives it superior storage stability and combustion properties.
Because of this composition, HVO is classified as a “drop-in” fuel. It can fully replace petroleum diesel rather than being blended in at limited percentages the way FAME biodiesel typically is.
Engine Compatibility
HVO meets the EN 15940 standard for paraffinic diesel fuels, and major engine manufacturers have approved its use. Cummins, for instance, has confirmed that its B4.5, B6.7, and L9 engine platforms (covering both on-highway and off-highway applications, across all production years) can run on 100% paraffinic renewable diesel meeting EN 15940. No engine modifications, no special fuel filters, and no additional maintenance are required.
The one practical requirement is that HVO sold under EN 15940 must include a lubricity additive, since the hydrotreating process strips out natural lubricating compounds found in petroleum diesel. Reputable fuel suppliers include this additive as standard, so for the end user, there’s nothing extra to do. You fill the tank and drive.
Emissions Reductions
HVO’s environmental case rests on two separate sets of numbers: what comes out of the tailpipe, and what happens across the full life cycle from feedstock to exhaust.
At the tailpipe, HVO reduces carbon dioxide emissions by 2% to 4% compared to fossil diesel. Nitrogen oxide emissions drop by 2% to 25%, depending on the engine and conditions. The biggest improvement is in particulate matter, the soot and fine particles linked to respiratory disease, which falls by 50% to 80%. These reductions trace back to HVO’s narrow carbon range and high cetane number, which produce a cleaner, more complete burn.
The life cycle picture is where HVO really stands out. When you account for the carbon absorbed by the original feedstock plants, the emissions from production, and the CO₂ released during combustion, HVO cuts total greenhouse gas emissions by 60% to 95% compared to fossil diesel. The exact figure depends heavily on the feedstock: waste cooking oil scores at the high end of that range, while virgin crop oils score lower because of the land use and farming emissions involved in growing them.
Storage and Shelf Life
One of HVO’s practical advantages over FAME biodiesel is how well it holds up in storage. Because it contains no oxygen and no biological ester bonds, it resists the oxidation and microbial growth that plague FAME blends. In storage stability testing over six months in both highland and coastal climates, fuel blends containing HVO maintained their physicochemical properties and stayed within diesel fuel standards for water content, viscosity, acidity, and oxidation stability.
For fleet operators or backup generator owners who keep fuel sitting in tanks for weeks or months, this matters. FAME biodiesel can degrade and cause filter clogging if it sits too long, especially in humid environments. HVO largely avoids this issue, making it a more practical choice for applications where fuel turnover is slow.
Regulatory Landscape in Europe
The EU’s revised Renewable Energy Directive (RED III) is reshaping the market for HVO. The directive requires member states to significantly increase the share of renewable fuels in transport by 2030, while phasing out reliance on first-generation biofuels made from food crops. This pushes demand toward waste-based HVO.
Analysis of Estonia’s fuel market illustrates the scale involved: meeting a 29% renewable energy target for transport using HVO alone would require replacing roughly 30% of the country’s diesel supply. A separate pathway in the directive focuses on reducing greenhouse gas intensity of transport fuels by at least 14.5% by 2030, which sets minimum quality thresholds for HVO based on what feedstock it’s made from. These requirements are driving investment in new HVO production capacity across Europe, with waste oils and animal fats as the preferred raw materials.
Limitations Worth Knowing
HVO isn’t without trade-offs. Global supply of waste cooking oil and animal fats is finite, and as demand grows, feedstock competition is intensifying. This keeps HVO more expensive than fossil diesel in most markets, sometimes significantly so. Production capacity is expanding but still falls far short of what would be needed to replace diesel at scale.
Cold weather performance is generally good, often better than FAME biodiesel, but varies by how the fuel is processed. Some HVO products are specifically engineered for arctic conditions, while others may need cold-flow additives in extreme climates. Checking the specific product specification matters if you’re operating in sub-zero temperatures.
The tailpipe CO₂ reduction of just 2% to 4% also means that, molecule for molecule during combustion, HVO releases nearly as much carbon dioxide as fossil diesel. Its climate benefit comes almost entirely from the renewable origin of that carbon, not from burning cleaner in the engine itself. This distinction matters when evaluating claims about HVO’s green credentials: the feedstock source and production method are everything.