How do lubricants work as shock-damping fluids in shock absorbers?

In shock absorbers, lubricants function as hydraulic fluids that facilitate viscous damping to control unwanted vehicle motion.12

When a vehicle encounters road irregularities, the resulting relative motion between the frame and the axle forces a piston to move within an oil-filled cylinder. As the piston slides, it forces the lubricant through small openings or spring-loaded valves. This process creates a resistive force that opposes the compression and stretching of the vehicle's springs, effectively dissipating the kinetic energy of the vibratory motion as heat.12

By forcing the fluid through these restricted passages, the shock absorber converts the mechanical energy of the springs into energy losses within the fluid, which prevents excessive bouncing and stabilizes the vehicle. This damping action is essential for maintaining control and comfort, as it regulates the rate at which energy is stored and released by the suspension system.23