Before we begin a discussion focused on performance degradation and the consequences of worn or damaged Struts and Shocks… And, the fact that “like new” performance is dialed in at the factory for just about 50,000 miles… It might be a better idea to start with a quick explanation of just what a McPherson Strut and/or a Shock Absorber is and exactly what it is they do? The purpose of a McPherson Strut or Shock Absorber is to control spring and/or suspension movement. In other words, the shocks and struts are there to mitigate or dampen road surface irregularities and imperfections: bumps, potholes, dips, etc. They are designed to reduce bounce, sway, roll acceleration squat or braking dip and/or dive.
Now, back to the design life of a Strut or Shock: It’s the truth! Fifty-Thousand Miles of like-new performance is what the factory shoots for when that Strut or Shock is first designed for that vehicle’s front or rear suspension. That doesn’t mean the Strut or Shock is likely to fall apart after just 50,000 miles! But, it does mean that the performance you can expect from that vital suspension component will begin to slowly degrade soon after that mileage milestone has been reached. Slowly is the operative expression in that last paragraph… In fact, the loss of performance is so slight and it takes place over such a long period of time it’s barely noticeable for most people. So, how can you know if or when it’s time to replace your Struts and/or Shocks. Here are a few of the same “Drive Test Tools” we use and the beauty of almost all of them is that you won’t have to drive your vehicle over 5 mph for most of them!