Yanmar Develops New Industrial Gas Engines

The new 4TN88G and 4TN98G engines utilize LPG, and will be introduced at bauma 2019.


Yanmar has developed gas-powered industrial engines that utilize LPG (liquid petroleum gas) and meet both U.S. EPA Tier 2, CARB Tier 4 and EU Stage V emissions regulations. Adding the two clean burning and quiet industrial engine models, the 4TN88G with maximum output 45.0 kW1 and 4TN98G offering maximum output 63.0 kW1 to its lineup, Yanmar is ready to better meet the diverse needs of its customers. Furthermore, Yanmar has plans to introduce bi-fuel2 specification models that can run on both LPG and gasoline.

Gas engines produce very little PM (particulate matter)3, and are comparatively quieter than diesels. This makes them ideal for work indoors and in enclosed areas, where environmental concerns are a major consideration.

Yanmar has more than 30 years of experience working with gas engines. This long-earned experience together with our deep knowledge of industrial diesel engine technology has allowed us to develop a proprietary gas combustion system for high output, fuel efficient and compact engines that display the durability and reliability required of industrial applications and deliver new value to our customers.

Yanmar can now provide customers with a “One-Stop Solution” whereby Yanmar can offer either a diesel or gas power source in one-stop sales contact, with maximum compatibility to the customer’s equipment.

With the addition of these new gas engines to Yanmar’s existing industrial engine lineup, Yanmar is well placed to meet customers’ demands with a versatile range of power solutions.

Main advantages

Higher specific power, Yanmar’s proprietary engine control system optimizes the air intake to achieve even greater power and torque than its diesel engines. The result is uncompromising performance for customers’ machinery with the benefits of using gas as a fuel.

Class leading fuel efficiency

With long experience in the development of gas engines, a combustion system optimized for LPG has been realized by implementing a high compression ratio and reducing intake pump loss. This has yielded fuel consumption reductions of 10%4 compared to current mixer systems5 resulting in longer operational hours for a same sized LPG tank, and reducing the lifecycle cost for the customer.

Endurance and reliability of a diesel engine block

Basing the engine on the superior endurance of Yanmar’s industrial diesel engine crankcase, together with optimized cooling systems and materials for heat resistance in high-temperature components such as cylinder head, intake and exhaust valves, and pistons, means that the endurance and reliability required of industrial engines is realized, even at the high combustion temperatures characteristic of stoichiometric combustion.

Compact engine configuration

Yanmar’s proprietary compact air-fuel mixing system results in a smaller engine (by approximately 9%) by eliminating the conventional gas engines with mixer system. Furthermore, our experience in installing industrial diesel engines to a variety of industrial machinery means that the engine layout is optimized to enable easy installation to forklifts, construction equipment, agricultural equipment and more.

Compatibility with diesel engines

By using the same application components and application software interfaces as those used with the machines and service tools on the market for use with Yanmar’s diesel engines, a high degree of compatibility has been secured between the diesel and gas engine installations.

1 Maximum outputs are the gross values based on SAE1995.
2 Bi-fuel engine: Engines that can run on both of LPG and gasoline fuel by implementing each fuel injection system on an engine
3 PM: Particulate matter are hazardous particles suspended in the air.
4 Figures calculated by comparing the tested value of Yanmar’s mixer-type gas engines with the new gas engines.
5 Mixer system: The system uses air-gas mixer which is designed with the structure of venturi effect.