HANS Head And Neck Support device

HC Hydrocarbons

HCCI Homogeneous combustion compression ignition

HDC Hill Descent Control (Land Rover)

HEGO Heated exhaust gas oxygen (sensor)

HID High intensity discharge (lamp)

HMI Human machine interface

hp Horsepower

HT High tension (high voltage)

HUD Head up display

HVAC Heating, ventilation and air conditioning