Aramco Reverses the Concept of 'Hybrid'. Will Combustion Engines Remain Constant in the Future?

Aramco has introduced a new hybrid propulsion system named DHE (Dedicated Hybrid Engine), a project that reverses the traditional foundations of hybrid engines. The work originates from Aramco Americas in collaboration with Pipo Moteurs, a manufacturer specializing in competition engines, and focuses primarily on efficiency.

The engineers started from a different approach compared to current hybrid engines. Rather than designing an electric engine that could accompany a combustion engine, they opted to develop a thermal engine that operates exclusively when paired with an electric one.

The result is a 1.6-liter three-cylinder engine designed to function solely as a generator. The configuration uses a block camshaft distribution with push rods, an outdated solution for a modern thermal engine, but effective in a context where it simply acts as support.

From a technical standpoint, the DHE utilizes long-stroke combustion chambers with an 82 mm bore and a 101 mm stroke. This choice reduces thermal losses and contributes to a declared efficiency of between 41% and 42%. According to the company's statements, future iterations could achieve compression ratios ranging from 13:1 to 15:1, prechamber ignition, and the possibility of hydrogen fuel.

Some might argue that this is merely a "range extender". Well, they wouldn’t be entirely wrong, as the principle is essentially the same. The thermal engine never transmits power to the wheels, but must go through two electric motors connected at the ends of the shaft via epicyclic couplings that provide traction. This configuration eliminates the need for a differential and allows movement with either the thermal engine on or off.

The main novelty likely lies in the scalability of the project, which allows the engine to adapt to practically any need. Aramco foresees 1.1-liter two-cylinder variants, up to 2.1-liter four-cylinder, and a 3.2-liter V6, available in both naturally aspirated and turbo versions.

According to the declared data, the system enables a fuel consumption reduction of up to 35% compared to current hybrid solutions. Costs are also lower, with an estimated cut of up to 25%, thanks to a simplification of the architecture and reduced mechanical complexity.

In conclusion, Aramco has not revolutionized the sector; it is not an especially astounding idea. Rather, it represents a radical shift in approach. With this solution, the hybrid concept does not root itself in combustion engines but in electric ones. Clearly, as the world's leading oil extractor, Aramco has every interest in ensuring a long life for combustion engines. At the same time, however, it must be acknowledged that this is undeniably a more ecological, economical, and sustainable approach. In light of the setbacks made by Europe, it could therefore prove to be a good compromise for the energy transition.