Stanadyne propane direct injection fuel system debuts

The propane direct injection fuel system is being featured in a GM 2023 Chevrolet Silverado 2500 HD. (Photo: Propane Education & Research Council)

Debuting at ACT Expo 2025 in Anaheim, Calif., this week is a new propane direct injection fuel system developed through a collaboration between Stanadyne, Katech and the Propane Education & Research Council (PERC). The technology will be featured in a GM 2023 Chevrolet Silverado 2500 HD, showcased in the PERC booth (#5113).

The integrated fuel system combines Stanadyne’s direct injection fuel pump with vapor lock technology and injector system with Katech’s vapor lock inhibitor to create a medium-duty engine capable of delivering propane autogas at up to 200-bar pressure directly into the combustion chamber. Integrated into the Silverado’s 6.6 L V8 L8T engine, the system produces 401 hp, 464 lb.-ft. of torque and enables a towing capacity of up to 17,370 lb. The test engine and vehicle required only minimal modifications.

“With our newly developed LPG direct injection pump and injectors, the system demonstrates strong potential for cost-effective scalability and broad commercialization,” said Srinu Gunturu, chief engineer at Stanadyne. “This technology not only reduces emissions but also makes clean propulsion more accessible for medium- and heavy-duty vehicles where electrification remains a challenge.”

The fuel system utilizes Stanadyne’s direct injection fuel pump with vapor lock technology and injector system. (Photo: Propane Education & Research Council)

During a 250-hour performance and durability test, the system successfully demonstrated compatibility with existing engines. Compared to diesel, propane autogas reduces nitrogen oxide (NOx) emissions by up to 96% and carbon dioxide (CO₂) emissions by 5% to 10%, said PERC.

“This solution delivers lower emissions, higher efficiency and the potential for significant cost savings because propane provides the lowest total cost of ownership,” added Gavin Hale, director of product development and power generation at PERC.

Several other propane-powered technologies will be featured at ACT Expo. Other products displayed in the PERC booth include:

• Alliance AutoGas Ford 7.3L V8 Bi-fuel System – This EPA-certified system provides an extended range as it can operate on both propane autogas and gasoline. The engine provides up to 430 hp and 475 lb.-ft. of torque.
• NEXIO 7.2L Supercharged V8 Propane Autogas Engine – Designed for Class 7 and 8 vehicles, this engine features a liquid injection system that can produce 330 hp and 775 lb.-ft. of torque. It is expected to meet or exceed EPA and CARB emissions standards.

In the Grand Promenade #9 is the MAFI Terminal Tractor equipped with a PSI 8.8 L propane autogas engine certified for mobile, off-road use. In a real-world study, the vehicle reduced NOx emissions by 99% compared with a diesel counterpart.

Part of the Ride and Drive program is the Pioneer e-Mobility e-Boost Mobile Charging Trailer. This off-grid EV charging solution includes a 75-kW propane-powered generator and a 60-kW DC fast charger. The trailer is designed to support mobile or remote EV charging needs.

PERC staff will be on site throughout the show to discuss these technologies and how propane is playing a growing role in clean energy solutions for transportation and other applications.

Research program reveals viability of LPG direct injection in medium-duty engines Funded by PERC and conducted by Katech Engineering, the project used software as well as specially designed hardware from Stanadyne to help overcome vapor lock.