Car struts are a common alternative to basic shocks. Although very similar in design and function, struts add a little more stability to a car's ride.
Car struts, which are basically just glorified shock absorbers, are used to stabilize the overall function and integrity of a car's suspension system. Along with leaf springs, coil springs, and stabilizer bars, struts add increased tension and support to a car's suspension system.
As a vehicle is driven over varying conditions, it has a tendency to bounce and hop depending on the roughness and/or bumpiness of a given road surface. Struts apply various degrees of tension to the front and rear of a vehicle that limit road bounce and bumpiness.
Without struts, a vehicle would be very hard to control and have a very harsh, erratic, jerky ride. Vehicle struts help to maintain vehicle control and ride by helping to evenly distribute vehicle body weight during the course of vehicle operation. Most vehicles have four struts---two in the rear, two in the front---that work in unison to maintain a controlled ride.
Struts absorb much of the stress and impact that a car experiences during operation. Without struts, a great deal of stress and pounding would be transferred directly to a car's frame, resulting in a very bumpy and choppy ride and, in extreme cases, frame damage.
Proper wheel alignment is crucial for the health of a car's tires as well as for maintaining adequate directional control. Struts exert tension on a car's wheels (both front and back), which helps to keep them in proper position and from bouncing up and down and swaying to the sides, all of which can negatively affect not only tire life but vehicle control.
