A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (for example, by the use of a throttle). The term throttle has come to refer, informally and incorrectly, to any mechanism by which the power or speed of an engine is regulated. Internal combustion engines In a petrol internal combustion engine, the throttle is a valve that directly regulates the amount of air ent… (More on Throttle)