A car hoist is a device that is used to raise a car up to allow access to underneath the vehicle. Commonly available in one-, two- and four-post styles, a car hoist is often an invaluable tool when working on the bottom of a vehicle. There are hydraulic versions of the car hoist, however, the electric models are the most commonly used types in home garages and shops. Models of the hoist are available in both ramp and chassis mount designs, with each offering its own positive and negative aspects with the chassis mount design offering the most versatility and access to most vehicles.
Many automobile repairs are more easily completed through the use of a car hoist as compared to working without a hoist. By using the car hoist to raise the car, access to chassis, exhaust and suspension components is placed within easy reach for the mechanic. The hoist is a heavy-duty device that commonly reaches under the car and connects to specific points on the vehicle's chassis to facilitate supporting the car when raised into the air. By activating an electric motor, the hoist is raised into the air by use of a threaded rod, or a hydraulic pump with hydraulic cylinders. Some older models of the hoist use an air-powered hydraulic cylinder to raise the vehicle.
The early versions of the car hoist used a single hydraulic cylinder to raise the car. This hoist commonly made it difficult to remove and replace entire exhaust systems. The difficulties stemmed from the placement of the cylinder and the chassis support being located in the center of the vehicle.
The four-post, ramp-style of car hoist solved the access problem by having the car be driven onto a pair of ramps that were raised at all four corners. This left the complete underneath of the chassis open. The problem with this type of hoist, however, is that the vehicle is required to sit on the tires, making access to wheels, brakes and shocks difficult.
To remove tires for maintenance, the four-post hoist required a car to be jacked up while on the hoist and placed on support stands. The two-post car hoist solved this problem by using two outboard arms that reach under the vehicle's chassis from the outer edge of the car. This allows the wheels to be removed while the car is in the raised position, as well as maintaining an open access underneath the car. This two-post design is the most commonly used car hoist in personal and commercial garages worldwide.