Aramco develops new hybrid engine

ARAMCO AMERICAS, a tech-focused subsidiary of Saudi Aramco, the world’s biggest integrated energy and chemical company, has developed a clean sheet hybrid engine that aims to cut costs, while at the same time boosting efficiency.

Engineers at the company’s US-based research outfit in Houston, Texas, have developed a new Dedicated Hybrid Engine (DHE) designed from the ground up, specifically for use in electrified applications.

Unlike conventional hybrid systems – which typically adapt an existing internal combustion engine for the role – the DHE has been engineered as a hybrid-first solution, integrating combustion and electric components into a simplified, cost-focused platform.

The project, led by senior combustion specialist Nayan Engineer at Aramco’s Detroit Research Centre, aims to deliver a powertrain that is not only more efficient, but also significantly cheaper and easier to manufacture.

Early modelling suggests the approach could reduce hybrid system costs by as much as 25 per cent when compared with current industry standards.

The concept was born from a simple question: What would an engine look like if it were designed for hybrid use from day one?

For Mr Engineer, the answer meant stripping away unnecessary complexity and focusing on real-world efficiency.

“Hybrids really are the best of both worlds,” he said, pointing to their ability to combine EV-like drivability with the range and flexibility of combustion engines.

Rather than retrofitting electrification onto a traditional engine, the DHE integrates electric motors at both ends of the crankshaft, enabling precise torque control and simplifying the drivetrain layout.

This dual motor-generator setup eliminates the need for a conventional differential while improving efficiency and packaging.

At the heart of the system is a compact 1.6-litre three-cylinder engine featuring a pushrod architecture, two valves per cylinder, and a monoblock design without a separate cylinder head.

While these elements may appear old-school, they are deliberately chosen to reduce cost, size, and complexity.

The engine operates within a narrow efficiency band – typical of hybrid applications – allowing it to prioritise thermal efficiency over outright performance.

Aramco claims thermal efficiency in the 41-42 per cent range, with further gains possible through advanced combustion techniques and higher compression ratios.

Additional innovations include roller-bearing internals to reduce friction, electrically driven auxiliary systems, and a long-stroke combustion layout designed to minimise heat loss.

To bring the concept to life, Aramco partnered with French motorsport specialist Pipo Moteurs, enabling rapid development from digital design to working prototype.

The project was intentionally kept lean, allowing engineers to move quickly without the delays typically associated with large-scale automotive programs.

Prototype engines have already been built and tested, validating the concept and paving the way for further development.

While the initial prototype targets mid-size SUV applications, the architecture is designed to be highly scalable.

Future variants could include two-cylinder, four-cylinder, and V6 configurations, with both naturally aspirated and turbocharged versions under consideration.

The system is also compatible with a range of electrified applications, including conventional hybrids, plug-in hybrids, and range-extender EVs.

Aramco estimates the DHE could deliver fuel consumption reductions of up to 35 per cent compared with conventional petrol engines, while maintaining a lower cost than many existing hybrid systems.

The development reflects a growing recognition that hybrid powertrains will play a critical role in the transition to full electrification, particularly in markets where charging infrastructure remains limited.

Mr Engineer said he believes the concept is especially relevant for emerging markets, where affordability and practicality remain key considerations.

“Hybrids solve real problems today,” he said.

“They work where charging infrastructure is limited and where cost matters.”

With patents secured and early prototypes validated, Aramco is now seeking industry partners to bring the technology to production.

The company has begun showcasing the DHE concept to automakers and suppliers, with the goal of integrating the architecture into future vehicle programs.

While it remains at an early stage, the clean-sheet approach challenges conventional thinking around hybrid systems – suggesting there may still be significant gains to be made in combustion-based efficiency, even as the industry accelerates toward electrification.

If adopted, the DHE could offer a compelling bridge technology, combining lower emissions and improved efficiency with the cost advantages needed to support mass-market adoption.