A bi-fuel vehicle has an Internal Combustion Engine (ICE) to provide motive power to the vehicle by combustion of a liquid fuel and gas-phase fuel. The vehicle has a dual fuel tank including a liquid fuel tank to receive liquid fuel, contain the liquid fuel, and supply the liquid fuel for combustion in the ICE. The vehicle has a pressurizable gas-phase fuel tank defined by a wall. A gas-phase fuel is permeable through the wall. The pressurizable gas-phase fuel tank is to receive the gas-phase fuel, contain the gas-phase fuel, and supply the gas-phase fuel for combustion in the ICE. A shell envelops the pressurizable gas-phase fuel tank and defines an interior space of the liquid fuel tank. The wall is in fluid communication with the interior space. The interior space is to receive the permeated gas-phase fuel.

A bi-fuel vehicle has an Internal Combustion Engine (ICE) to provide motive power to the vehicle by combustion of a liquid fuel and gas-phase fuel. The vehicle has a dual fuel tank including a liquid fuel tank to receive liquid fuel, contain the liquid fuel, and supply the liquid fuel for combustion in the ICE. The vehicle has a pressurizable gas-phase fuel tank defined by a wall. A gas-phase fuel is permeable through the wall. The pressurizable gas-phase fuel tank is to receive the gas-phase fuel, contain the gas-phase fuel, and supply the gas-phase fuel for combustion in the ICE. A shell envelops the pressurizable gas-phase fuel tank and defines an interior space of the liquid fuel tank. The wall is in fluid communication with the interior space. The interior space is to receive the permeated gas-phase fuel.

A prechamber is provided for attachment to an inlet of a combustion chamber of an internal combustion engine. The prechamber decreases the compression ratio of the combustion chamber. Some examples of the prechamber include a means of adding a spark plug to an engine that was originally designed to ignite fuel/air through compression of the fuel/air. Other examples of the prechamber include internal structures to introduce swirl in fuel/air as it is injected. Still other examples of the prechamber include a plurality of fuel injectors, with each fuel injector being structured to introduce a different type of fuel into the prechamber. A means of selecting a specific type of fuel based on engine operating conditions is also provided.

A controller injects fuel into a cylinder at a high fuel pressure of 30 MPa or higher, at least in a period between a terminal stage of a compression stroke and an initial stage of an expansion stroke when an operating mode of an engine body is at least in a first specified sub-range of a low load range, and at least in a second specified sub-range of a high load range. The controller sets an EGR ratio in the first specified sub-range to be higher than an EGR ratio in the second specified sub-range, and advances start of fuel injection in the first specified sub-range to start of fuel injection in the second specified sub-range.

A controller injects fuel into a cylinder at a high fuel pressure of 30 MPa or higher, at least in a period between a terminal stage of a compression stroke and an initial stage of an expansion stroke when an operating mode of an engine body is at least in a first specified sub-range of a low load range, and at least in a second specified sub-range of a high load range. The controller sets an EGR ratio in the first specified sub-range to be higher than an EGR ratio in the second specified sub-range, and advances start of fuel injection in the first specified sub-range to start of fuel injection in the second specified sub-range.

An opposed-piston engine system equipped for full hybrid compressed-air/combustion includes capacity for storing air compressed by the engine during a combustion mode of operation. The hybrid opposed-piston engine system includes a control mechanization for operating the opposed-piston engine in a combustion mode by provision of fuel, in a compressed-air mode by provision of stored compressed air, and in a combustion mode supplemented by provision of stored compressed air. A method of operating a hybrid vehicle equipped with an opposed-piston engine includes storing air compressed by the engine during a combustion mode of operation and operating in the vehicle a compressed-air mode by provision of stored compressed air.

An opposed-piston engine system equipped for full hybrid compressed-air/combustion includes capacity for storing air compressed by the engine during a combustion mode of operation. The hybrid opposed-piston engine system includes a control mechanization for operating the opposed-piston engine in a combustion mode by provision of fuel, in a compressed-air mode by provision of stored compressed air, and in a combustion mode supplemented by provision of stored compressed air. A method of operating a hybrid vehicle equipped with an opposed-piston engine includes storing air compressed by the engine during a combustion mode of operation and operating in the vehicle a compressed-air mode by provision of stored compressed air.

An opposed-piston engine system equipped for full hybrid compressed-air/combustion includes capacity for storing air compressed by the engine during a combustion mode of operation. The hybrid opposed-piston engine system includes a control mechanization for operating the opposed-piston engine in a combustion mode by provision of fuel, in a compressed-air mode by provision of stored compressed air, and in a combustion mode supplemented by provision of stored compressed air. A method of operating a hybrid vehicle equipped with an opposed-piston engine includes storing air compressed by the engine during a combustion mode of operation and operating in the vehicle a compressed-air mode by provision of stored compressed air.

An opposed-piston engine system equipped for full hybrid compressed-air/combustion includes capacity for storing air compressed by the engine during a combustion mode of operation. The hybrid opposed-piston engine system includes a control mechanization for operating the opposed-piston engine in a combustion mode by provision of fuel, in a compressed-air mode by provision of stored compressed air, and in a combustion mode supplemented by provision of stored compressed air. A method of operating a hybrid vehicle equipped with an opposed-piston engine includes storing air compressed by the engine during a combustion mode of operation and operating in the vehicle a compressed-air mode by provision of stored compressed air.

A thermal choke, includes (1) a body, comprising a heat conductive material, (2) an electric heater, on or in the body, (3) a temperature sensor, on or in the body, and (4) a fin, in a channel surrounded by the body. The thermal choke is configured to fit between a throttle assembly and a cylinder of a spark ignition engine.