In the UK, where sustainability and efficiency are becoming paramount across sectors, HVO fuel (Hydrotreated Vegetable Oil) is gaining rapid popularity as an eco-friendly diesel alternative. Marketed for its cleaner emissions, longer shelf life, and better cold-weather performance, HVO is particularly appealing to businesses looking to reduce their carbon footprint. But as with any emerging fuel technology, practical concerns arise—can HVO fuel cause fuel system corrosion?

Understanding HVO Fuel: What Is It?

Hydrotreated Vegetable Oil (HVO) is a synthetic paraffinic diesel made through hydrotreatment of waste vegetable oils and animal fats. Unlike traditional biodiesel (FAME), which contains esters and oxygen, HVO is completely free of oxygen, making it chemically closer to fossil diesel.

Key Features:

• High cetane number (typically above 70)

• No aromatics or sulphur

• Excellent storage stability

• Biodegradable and non-toxic

• Approved under BS EN 15940:2016 fuel standard

The Corrosion Question: What’s the Concern?

Corrosion in fuel systems typically occurs due to:

• Water contamination

• Acidic compounds

• Oxidation by-products

• Microbial growth

So the main concern here is: Does HVO introduce or accelerate any of these corrosive factors into the fuel system?

Let’s explore this in detail.

1. HVO’s Chemical Properties: No Oxygen, No Problem?

One of the main reasons corrosion occurs in traditional diesel systems—especially with FAME biodiesel—is due to the presence of oxygen and water-absorbing esters, which lead to microbial growth and acidic by-products.

HVO, being oxygen-free and hydrophobic, does not attract water in the same way. This greatly reduces microbial growth and consequently, the risk of microbial corrosion.

Verdict:
HVO fuel is chemically stable and less likely to cause fuel system corrosion compared to FAME biodiesel or even standard diesel blends.

2. Water Contamination and Corrosion: Still a Risk?

While HVO is less hygroscopic, water contamination is still possible, especially during storage and transport. Condensation in poorly sealed tanks or mixing with legacy fuel can introduce moisture. In turn, this can encourage corrosion in:

• Steel or iron tanks

• Older pipework and seals

• Low-grade metal components in injectors or pumps

In the UK, where moist climates are common, even HVO users must take precautionary tank maintenance seriously.

Best Practices:

• Drain water from storage tanks regularly

• Use water separators in filters

• Perform microbial testing periodically

Verdict:
HVO doesn’t cause water-related corrosion—but poor fuel storage and handling still can.

 3. Is HVO Compatible with Existing Fuel Systems?

According to UK fuel experts and engine manufacturers like Scania, Volvo, and John Deere, HVO is fully compatible with most modern diesel engines and fuel systems without modification. This includes:

• Fuel lines

• Seals

• Injectors

• High-pressure pumps

However, older vehicles (especially pre-2000s) may have seals and elastomers not rated for paraffinic fuels. In rare cases, seal shrinkage or leakage may occur.

What to Do:

• Check OEM guidance

• Use HVO as a blend initially

• Monitor for leaks after switching

Verdict:
HVO is mostly safe, but older engines may require upgraded materials to avoid compatibility issues.

4. HVO Additives: A Hidden Risk?

Some suppliers in the UK may add performance additives to HVO fuel for:

• Cold flow improvement

• Detergency

• Lubricity enhancement

If improperly formulated, these additives could alter the chemical balance of the fuel, leading to sediment formation, filter plugging, or corrosion. However, reputable UK suppliers use additives fully tested under EN 15940 standards.

Pro Tip:
Choose certified UK suppliers with transparent additive disclosure.

Verdict:
Additives are safe when used correctly. Check your supplier’s specifications.

🇬🇧 UK Case Studies and Real-World Feedback

UK haulage, farming, and construction industries using HVO have not reported increased corrosion in properly maintained systems. In fact, most feedback suggests:

• Cleaner injectors

• Fewer filter changes

• No microbial fouling

A 2023 study by the UK’s Renewable Fuels Association confirmed that no corrosion-related failures were linked directly to pure HVO usage.

How to Make HVO Safer: Best Practices

To ensure long-term fuel system health with HVO in the UK:

1. Use BS EN 15940-certified HVO

2. Store in clean, water-free tanks

3. Test for water and microbial presence every 6 months

4. Check compatibility of older vehicles before switching

5. Stick with UK-trusted suppliers

Final Verdict: Can HVO Fuel Cause Fuel System Corrosion?

Short answer: No, not inherently.
Long answer: When handled, stored, and sourced correctly, HVO is among the safest fuels available in terms of fuel system corrosion. In fact, it's more stable and cleaner-burning than standard diesel or biodiesel.

However, user practices—not the fuel itself—remain the biggest risk factor. Neglecting tank hygiene, mixing fuels improperly, or using unverified sources can invite corrosion problems.

Closing Thoughts

For UK businesses transitioning to greener fuels, HVO fuel is not only a climate-friendly option—it’s also a mechanically safe one. With proper maintenance, you’ll not only avoid corrosion, but also enjoy better engine performance, lower emissions, and longer service intervals.

So, does HVO cause fuel system corrosion?
Not if you do your part right.