Speed and driving style have nothing to do with how long struts last. If that were the case, I'd have gone through ten sets by now. My Grand Caravan has 251,000 miles, is 25 years old, and the struts are original. That isn't typical, but there is no typical time for struts and shock absorbers to fail or wear out.
Start by looking at the top of the strut body where the shaft comes out, and look for oil running down from there. That's a definite sign it's time to replace them. A bounce test will also usually show if they aren't dampening like they're supposed to. Even when there's no leakage, it is not uncommon to experience a bouncy ride after a long trip. Forcing the hydraulic oil through the tiny ports causes it to get pretty hot, and that makes it thin out and become less effective.
We don't get involved with costs here because there's way too many variables, but as a general guess, a pair of struts will cost around $100.00 per pair, less for domestic cars, and will take about an hour to replace. The car will need to be aligned after the struts are replaced.
SPONSORED LINKS
Wednesday, February 26th, 2014 AT 1:33 PM