Cars need regular replacement of shocks or struts every 50,000 miles or so, depending on your car's make and model. Have your mechanic make a routine check of the shocks or struts every 50,000 miles, or however often your operating manual recommends it.
How often should a struts be replaced?
Generally, shocks and struts wear out every 50,000-100,000 miles. If you're a more aggressive driver and/or frequently drive on rough roads, they will wear out faster. Shocks and struts don't go out all at once; they deteriorate slowly over time.
What is the average life of a strut?
On average, if your car has been “babied,” you can expect your shocks/struts to last about 10 years. If you have really used your car like a workhorse, 5 years is probably all you can expect. This means that for the average driver, 7 or 8 years is the maximum life expectancy of most shocks and struts.