I will take issue with coil springs.

Sway bars do not wear out like springs. Suspension coil prings are under continuous load and with time they take a set. This compression set results in vehicle sag, and usually means the coil springs need to be replaced, or spacers need to be added to take up the lost compressed height. Though the coil springs may sag, the spring constant will remain the same.

Sway bars, on the other hand, are under neutral load and will continue to function as designed, and with time they will have no noticeable loss in performance. There is no "set" associated with a sway bar.

OK, I wasn't being completely scientific either and to say they wear out "like" each other wasn't exactly precise. The fact remains, a sway bar does wear out after a lot of flex(mileage) and therefore, as mentioned, it depends on how the vehicle is being driven. if you are mostly driving on highways/country roads, you may never experience a wear on the sway bar no matter what the mileage. But if you are flexing that thing on a daily basis on surface streets, urban blocks with lots of turning, swaying, etc, etc, the bar will wear out faster - but wear out nonetheless. Yes, it will probably outlive everything else on the car, and most likely the car itself...

I have never seen nor heard of one wearing out.

The exception is the front on a benz and I have heard of several that the end broke off of. But its a part of the suspension so its loading is different.

Tom W

I fail to see how a sway bar car wear out. What happens with age and use? What does it fail to do after repeated flexing?