Trying to put a time or mileage limit on how long brake pads and rotors should last is harder than trying to predict what kind of gas mileage you should expect. Brake life depends on how much we drive, where we drive (think city versus highway) and how we drive (meaning lead foot versus slow and steady).
As a guideline, brakes will wear out much faster if most of your driving is in a major urban area where stop-and-go is the rule, as opposed to those who spend most of their miles on the open road, where they might not touch the brake pedal for an hour or more.
If you drive in Boston, New York City or Chicago and spend more time stopping than going, you could need new brake pads every 15,000 miles. If you live in western Iowa and commute from Moville to Holstein, your pads could last three or four times that.
But if you're a driver who frequently applies the brakes when it isn't necessary — or even drives with one foot on the gas pedal and the other on the brake — it might not matter where you live. Your brakes are going to wear out sooner than later.
If you own a hybrid or electric vehicle, your brakes should last longer because the regenerative brake systems they use provide much of the stopping power, reducing wear on the pads and rotors. In addition, applying the brakes early for a slow, gradual stop doesn't increase brake wear, and it helps recharge the batteries for powering the electric motor. Some hybrid owners say their pads and rotors have lasted more than 80,000 miles.
Brakes wear gradually, so you might not notice a mild but steady degradation in stopping ability, or that the pedal goes farther down when you apply the brakes (which is one sign that the pads are worn).
Your ears can help. Turn off the stereo and listen when you apply the brakes. Squeals, squeaks and rattles are indications that your brakes need attention, though they don't necessarily mean you need new pads and/or rotors. A metal-to-metal grinding sound, on the other hand, probably means your pads are worn down so far that it's well past time to replace them.
Because brakes are so important, monitor their condition instead of waiting for something to go wrong. For example, some rotors can be resurfaced for far less than it would cost to replace them if you don't wait until they're too far gone and have to be scrapped.
After the first year or so of driving a new car, it's a good idea to have the brakes inspected at each oil change. Repair shops can measure pad thickness, plus check the condition of the rotors, calipers and associated hardware, and the brake fluid, and give you a status report.
You might not need brake work that day, but it's better to know than to guess — and be wrong.
