What holds the car hood up?

A hood strut, also known as a gas strut or lift support, holds the car hood up. It is a mechanical device that uses gas pressure to provide the force needed to lift and hold the hood open. Hood struts are typically made of a cylindrical metal tube filled with compressed nitrogen gas, and they have a piston that moves inside the tube to control the release of gas pressure. When the hood is opened, the gas pressure extends the strut and lifts the hood up to a certain point. The strut then locks in place, keeping the hood open until it is manually closed.