An electric gas flow heater has a grid-like heating element through which exhaust gas can flow axially, and which forms an electrical resistance heating. The grid-like heating element includes radially successive layers of band-like material, wherein the layers, in an axial view of the heating element, are bent in an undulating manner and include valleys and peaks. The layers that are located between the radially outermost layer and the radially innermost layer are attached by their peaks and valleys to the respectively radially adjacent layer, so that flow-through openings are formed between the layers. The wavelengths of the layers are increasing radially outwards.

A dual-chamber onboard electrolysis system is configured to produce HHO gas for heavy duty trucking applications.

A dual-chamber electrolysis vessel safely stores HHO gas for use by an internal combustion engine.

Timing of HHO gas injection into a 4-stroke engine is optimized based on engine operating parameters to improve fuel economy.

An exhaust aftertreatment system for use with over-the-road vehicle is disclosed. The exhaust aftertreatment system includes a reducing agent mixer with a mixing can and a flash-boil doser configured to inject heated and pressurized reducing agent into the mixing can for distribution throughout exhaust gases passed through the mixing can.

An exhaust aftertreatment system for use with over-the-road vehicle is disclosed. The exhaust aftertreatment system includes a reducing agent mixer with a mixing can and a heated doser unit configured to inject heated reducing agent into the mixing can for distribution throughout exhaust gases passed through the mixing can. Heating of reducing agent may be selectively applied based on a variety of inputs to a controller.

Methods and systems are provided for an aftertreatment system. In one example, a method comprises regenerating a NO.sub.x trap during an engine shut-down event. The method further comprises reversing a direction of flow of a gas through a HP-EGR passage during the regenerating.

An exhaust aftertreatment system for use with over-the-road vehicle is disclosed. The exhaust aftertreatment system includes a reducing agent mixer with a mixing can and a heated doser unit configured to inject heated reducing agent into the mixing can for distribution throughout exhaust gases passed through the mixing can. Heating of reducing agent may be selectively applied based on a variety of inputs to a controller.

An electric gas flow heater has a grid-like heating element through which exhaust gas can flow axially, and which forms an electrical resistance heating. The grid-like heating element includes radially successive layers of band-like material, wherein the layers, in an axial view of the heating element, are bent in an undulating manner and include valleys and peaks. The layers that are located between the radially outermost layer and the radially innermost layer are attached by their peaks and valleys to the respectively radially adjacent layer, so that flow-through openings are formed between the layers. The wavelengths of the layers are increasing radially outwards.

An exhaust aftertreatment system for use with over-the-road vehicle is disclosed. The exhaust aftertreatment system includes a reducing agent mixer with a mixing can and a flash-boil doser configured to inject heated and pressurized reducing agent into the mixing can for distribution throughout exhaust gases passed through the mixing can.