The Road Ahead Is Changing

For decades, diesel has been the heartbeat of the trucking industry. It’s reliable, energy-dense, and easy to refuel. But it’s also under pressure — from emissions regulations, fuel price volatility, and the growing demand for greener supply chains.

While battery-electric and hydrogen fuel-cell trucks get the headlines, many fleets can’t justify the cost of replacing perfectly functional diesel assets. The good news? There’s a smarter middle ground.

Enter hydrogen-diesel blending — a straightforward retrofit solution that lets your existing trucks run cleaner, smoother, and more efficiently. Using hydrogen to increase the efficiency burn of the diesel resulting in much cleaner emissions and less diesel used.

“Most fleet operators don’t want to scrap good assets just to meet emission targets,” says Edgar La Pointe, ESSNA™ H2 Fleet Service. “Hydrogen blending is a way to start decarbonizing today — without overhauling your entire fleet tomorrow.”

What Is Hydrogen-Diesel Blending?

Hydrogen-diesel blending (sometimes called dual-fuel) injects hydrogen alongside diesel in the engine’s combustion chamber.  

That means:

• The engine still runs like a diesel — same power, same torque.

• You burn less diesel fuel.

• You emit less CO₂, soot, and hydrocarbons.

Depending on the retrofit design, a hydrogen-diesel blend can reduce Carbon Intensity anywhere from 20% to 60%  with hydrogen during operation.

At the University of New South Wales, researchers demonstrated a diesel engine running on up to 90% hydrogen, cutting CO₂ emissions by 85.9% compared to the baseline diesel mode.

And in New Zealand, HW Richardson Group — one of the country’s largest trucking firms — has trialled hydrogen-diesel trucks and reduced carbon emissions by roughly 30%.

It’s not a science experiment anymore — it’s a viable bridge solution.

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The Science Behind the Blend

When you introduce hydrogen into a diesel engine, you’re improving combustion:

• Hydrogen burns faster and cleaner, ignition is quick

• Soot and carbon monoxide drop sharply, thanks to more efficient flame propagation.

• Fuel efficiency improves slightly, particularly in steady-load operations.

A recent review from the Royal Society of Chemistry found that dual-fuel hydrogen engines can reduce particulate matter by up to 95% and CO₂ by 40–85%, depending on blending ratios and control systems.

There’s nuance, of course — nitrogen oxides (NOₓ) can increase under certain loads if not properly managed. That’s why ESSNA™’s retrofits include engine calibration, EGR tuning, and hydrogen control logic to ensure compliance and stability.

“Hydrogen blending only works when it’s done right,” says Gareth Gregory, ESSNA™ head. “Our team doesn’t just bolt on new hardware — we calibrate the entire system to match the truck’s duty cycle and emissions requirement.”

Real-World Results: Proof on the Road

Several real-world trials and technical studies show how moderate hydrogen-diesel blends — typically between 6% and 30% hydrogen by energy — deliver meaningful emissions and efficiency gains while maintaining the same power and reliability that fleets expect.

• HYDI (Australia / New Zealand): A Wellington bus fleet testing a hydrogen-assist retrofit reported a ~10% reduction in diesel consumption over six weeks, demonstrating practical fuel savings and cleaner combustion at low blend levels.

• Aberdeen City Council (UK): Fleet vehicles running on hydrogen-diesel dual-fuel systems achieved up to 30% lower CO₂ emissions compared to standard diesel models — with no drop in reliability or operating range.

• MDPI Experimental Study (2023): Independent combustion research found that modest hydrogen substitution at under 25% improved thermal efficiency and reduced CO₂ by around 17%, confirming gains without major engine modifications.

These results prove that you don’t need extreme blends to see real progress.
Even 6%–30% hydrogen ratios can deliver 20–30% CO₂ reductions, smoother combustion, and lower soot — all while keeping trucks running like the diesel engines operators know and trust.

The Fleet Advantage: Economics, Emissions, and Ease

Let’s break it down from a fleet manager’s point of view.

1. Lower Diesel Consumption

If your trucks average 50,000 L of diesel per year, a 40% hydrogen blend saves 20,000 L — that’s about 53 t of CO₂ avoided per truck. Multiply that across a 100-truck fleet, and you’re cutting 5,300 t of CO₂ annually.

2. Fuel Cost Hedge

Hydrogen prices vary, but as green hydrogen production scales, costs are trending down. By sourcing hydrogen through ESSNA™’s on-site hydrogen systems, fleets can stabilize long-term fuel expenses and partially shield themselves from diesel volatility.

3. Minimal Downtime

Unlike full vehicle replacement, a retrofit can be done in a couple hours — not months. Trucks return to service quickly, keeping utilization high.

4. Future-Proof Transition

Hydrogen-diesel blending doesn’t lock you in. It lets you start now, test hydrogen fueling logistics, and build experience while the market matures for full fuel-cell or electric trucks.

“Hydrogen blending is like putting one foot in the future and keeping the other in today’s reality,” Gregory adds. “It’s the smartest way to move forward without stopping your business.” Gregory also warns of using outdated diesel-hydrogen blend technologies that are bringing the market down and wasting market subsidies, ‘we plan to publish a detailed overview on this in the near term, correcting the misrepresentation put forward by companies that are a decade plus outdated’.

“Hydrogen blending is like putting one foot in the future and keeping the other in today’s reality, It’s the smartest way to move forward without stopping your business.”

Retrofit vs. Replacement: The Pragmatic Choice

Fleets can retrofit now, reduce diesel usage immediately, and still pivot later to pure hydrogen or electric — when the infrastructure and incentives align.

Inside the ESSNA™ Hydrogen-Diesel Retrofit

ESSNA™’s engineers have developed a modular system designed for heavy-duty fleet operations.

How It Works:

1. Assessment: ESSNA develops the baseline on a pilot program basis.

2. Retrofit: 2 to 4 hour installation depending on brand and model.  

3. Calibration: Calibration: Algorithmically optimized for real-time hydrogen–diesel blending, ensuring stable combustion, efficiency, and emission control.

4. Monitoring: Real-time telemetry ensures safety, efficiency, and fallback to full diesel mode if needed.

5. Support: Ongoing service, updates, and hydrogen sourcing strategy.

Why It Works:

• Compatible with most common diesel platforms

• Minimal downtime for installation

• Proven emissions and fuel performance

• Seamless fallback to diesel when hydrogen isn’t available

Overcoming Common Concerns

“Hydrogen is expensive.”
Hydrogen is nearing diesel parity.

“What about reliability?”
ESSNA™’s retrofits are designed for fail-safe operation with low probability of breakdown due to the innovative design.

“Will it void my warranty?”
Our retrofit is non-destructive and fully reversible. ESSNA™works with certified installers and supports documentation for compliance and OEM coordination.

The Road to Lower Carbon Intensity Starts Here

Hydrogen isn’t a far-off future — it’s here, and it works today. Retrofitting diesel trucks for hydrogen-diesel blends gives fleets a faster, lower-risk path to decarbonization, fuel flexibility, and long-term resilience.

ESSNA™ provides turnkey hydrogen retrofit services — from engineering and calibration to hydrogen supply and after-install support — so your fleet can move cleaner further on less diesel.

“Fleets that act early gain a competitive edge,” says Gregory. “Hydrogen-diesel blending isn’t just about emissions — it’s about fuel control, operational resilience, and future readiness.”

Let’s Talk Hydrogen

Ready to explore a retrofit for your fleet? ESSNA™ can run a feasibility analysis, calculate return, and design a pilot program tailored to your routes and trucks.

Contact Edgar today to start the conversation.

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