Regular shocks use hydraulic fluid and air as their dampening system. Premium quality shocks and struts use compressed nitrogen gas instead of air. Gas shocks don’t get air bubbles that affect the performance of regular shocks. If you do a lot of high performance driving, off-roading or just want added comfort and control, think about getting premium gas shocks or struts.
Replacing your struts may take your car out of alignment, so be sure to get an alignment at the same time. So, to smooth out the bumps on the road of life, change your shocks and struts when they need it.