Difference Between Gas And Oil Shock Absorbers

Regardless of whether they are gas or oil shock absorbers , the important thing about this vehicle component is that it keeps the tire glued to the ground at all times.

That is, in addition to making us more comfortable and noticing less bumps and irregularities in the terrain, shock absorbers are a fundamental part of active safety that protects occupants and other elements of the vehicle from shocks, impacts and vibrations.

However, although the operation of the gas or oil shock absorbers is the same, the performance of each one of them presents great differences , and those are what we will see below.

What is the shock absorber for?

Shock absorbers are responsible for absorbing energy when there is a displacement in the mass of the vehicle when traveling on uneven terrain, converting kinetic energy into thermal energy. They are located between the chassis and the wheels of the vehicle.

They usually consist of a chrome-plated axle anchored to the vehicle and two steel tubes , a reserve one (located on the outside) and a compression tube (on the inside). The piston, located at the other end of the vehicle, moves the compression tube which, by exerting pressure, sucks the fluid, causing it to circulate through the valves of the same.

If the shock absorber is too stiff it diminishes the comfort, but if it is too soft, it can get to lose control of the vehicle. In addition, excessive wear of this component can jeopardize our safety.

Difference between gas and oil shock absorbers

The operation of the shock absorbers is based on the circulation of the fluid between the internal devices through a set of valves that, as it passes, generate a resistance between the chambers.

The initial position (called the expansion phase ) is that of the piston located in the center of the pressure tube and overflowing with fluid, while the reserve tube is partially covered.

When the wheel goes over a bump, the compression phase is activated . That is, the spring contracts and absorbs the kinetic energy of the impact. Then the piston enters the pressure tube and actuates the damper. The fluid exerts strong pressure on the mechanism , which helps to assimilate this energy and transform it into heat energy so that, finally, it is eliminated through the hydraulic system.

The type of fluid that is responsible for mitigating the movement is what makes the difference between gas and oil shock absorbers. Gas shock absorbers also have oil, but their chambers, in addition to containing air, have nitrogen gas , which facilitates the return of the fluid to the chambers, making the tires contact the ground faster.

Gas shock absorbers

Gas shock absorbers have many advantages over oil shock absorbers. The main one is that they improve the adhesion of the tires to the asphalt.

Having nitrogen gas is what allows the oil to flow back into the chambers more quickly, making all-wheel grip much greater in extreme situations, such as going through sharp corners at very high speeds. In fact, gas shocks are perfect for driving on very rough terrain.

Although they do not totally eliminate the risk of the oil reaching a boil, they greatly minimize the formation of bubbles. This translates into a more efficient work of this component.

They are stiffer than those made of oil, that is, the shock absorption is drier. This makes for greater control over steering and braking, but also makes potholes felt inside the vehicle more.

Finally, it should be noted that nitrogen reduces oil degradation by heat, since it is capable of working at lower temperatures. That is, the gas are the most durable .

Oil or hydraulic shock absorbers

This type of shock absorber works only with oil and consists of two air chambers. Through valves, the oil enters from one chamber to another, according to the movement of the stem.

They are not as stiff as gas, so they are not as efficient. But instead, they provide a smoother and more comfortable driving , since when the vehicle enters a pothole they are able to absorb the impact better, and inside the cabin it is hardly perceived. In addition, they hardly need maintenance.