5 Minutes
Romania Delivers a Breakthrough: LPG Direct Injection Meets Mild Hybrid
Horse Technologies, the Romania-based engineering company born from a partnership between Renault Group and the Geely Fund, has started production of a genuinely novel powertrain: the HR12 LPG, the world's first mass-produced liquified petroleum gas (LPG) engine to use direct injection. Designed as a bi-fuel unit that runs on both gasoline and LPG, the HR12 LPG brings direct-injection precision to alternative-fuel combustion while pairing it with a 48‑volt mild‑hybrid system for improved efficiency and drivability.
Cutting‑Edge Powertrain Technology
The HR12 LPG is a turbocharged 1.2‑liter three‑cylinder engine engineered for modern passenger cars. Its headline features include an LPG-specific direct injection system, an electronic vaporizer for accurate fuel phase and pressure control, strengthened internal components to handle higher pressures, and a belt-driven starter-generator with DC/DC converter as part of a 48‑volt mild‑hybrid setup. That combination enables quicker torque delivery, lower fuel consumption, and reduced CO2 emissions compared with conventional gasoline operation.
Key Specifications
- Engine: 1.2‑liter turbocharged inline‑3 (HR12 LPG)
- Power: 138 hp (at 5,500 rpm)
- Torque: 170 lb‑ft (available from ~2,100 rpm)
- Fuel types: Gasoline and LPG (direct injection for LPG)
- Hybrid system: 48‑volt mild‑hybrid with belt‑driven starter‑generator and DC/DC converter
- Emissions: ~9% lower CO2 on LPG vs gasoline; Euro 6e compliant and prepared for future Euro 7 standards
- Production capacity: Horse Technologies plant in Mioveni — up to 450,000 engines/year
Design and Packaging
The HR12 LPG incorporates an LPG tank installed in the spare wheel well, preserving passenger and cargo space — a practical choice for OEMs and fleet buyers. The fuel system itself is fully redesigned for direct injection LPG: injectors and fuel rail are tailored to handle the physical properties of liquified petroleum, and an electronic vaporizer ensures the correct fuel state and pressure are delivered to the combustion chamber. Reinforced pistons, rods, and valvetrain elements increase durability under LPG operation.
Performance and Efficiency
With 138 hp and 170 lb‑ft available at low rpm, the HR12 LPG is aimed at everyday drivability rather than outright performance. The 48‑volt mild‑hybrid component supplies extra torque during acceleration and enables smoother engine restarts, improving urban fuel economy and lowering tailpipe CO2. When running on LPG, the direct‑injection strategy allows more precise air‑fuel control and better thermal efficiency than legacy indirect‑injection LPG systems, delivering measurable CO2 reductions and improved fuel consumption.
Market Positioning and Competitiveness
Horse Technologies positions the HR12 LPG as a pragmatic, low‑emission alternative for volume production — a solution that appeals to regions with established LPG infrastructure and to automakers seeking lower lifecycle CO2 for small and mid‑sized vehicles. The combination of a modern turbocharged gasoline architecture, LPG direct injection, and mild‑hybrid assistance is unique in the market: most bi‑fuel engines today still rely on vaporized LPG mixed with intake air (indirect injection), which limits efficiency and combustion control compared with direct injection.
How It Compares
Compared with traditional gasoline-only 1.2‑liter turbo engines, the HR12 LPG adds fuel flexibility and the potential for lower running costs where LPG is cheaper than gasoline. Versus conventional LPG conversions and legacy factory bi‑fuel engines, the HR12's direct injection offers tighter combustion control, improved power delivery, and better emissions. Against full hybrid or battery electric powertrains, it remains a lower‑cost, quick‑to‑deploy option for markets where electrification is constrained by infrastructure or cost considerations.
Why It Matters
As OEMs diversify powertrain portfolios to meet stricter CO2 regulations and varied regional needs, the HR12 LPG demonstrates an alternative path: advanced internal combustion that reduces emissions through fuel innovation and mild electrification. Produced at scale in Mioveni and engineered to meet upcoming emissions rules, the HR12 LPG is likely to attract attention from manufacturers targeting fleets, emerging markets, and drivers seeking lower fuel bills without sacrificing cabin space or everyday usability.
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