Dear Car Talk:
I have a 2014 Nissan Altima with 74,000 miles that I bought new. The miles are 90% highway miles on cruise control. I don't drive in rush-hour type traffic.
How is brake life supposed to be determined if we all drive in different driving conditions? What should the life expectancy of my brake pads and rotors be?
I'm concerned that dealers, with so few cars on their lots to sell these days, are pushing "repairs" to increase profits, and I'm not savvy enough to know whether to believe them when they say I need brakes. -- Larry
It's likely you need brakes, Larry.
Brake life is based entirely on usage. The more you use the brakes, and the harder you use the brakes, the shorter their life. Most cars, under a normal mix of highway and city driving, will go through a set of brakes every 30,000 miles or so.
But that's an average. If you drive like a New York City cabby, you might need brakes every 15,000 miles. If you do all your driving on the highway, and gently coast to a stop on off-ramps, you could get 90,000 miles out of a set of brakes.
So, based on your mileage alone, you should be close to needing new pads and rotors if you don't need them already. But you don't have to guess based on mileage, Larry. There are objective ways to measure brake life.
There is a gauge that measures the thickness of your remaining brake pads. And generally speaking, if they're down to an eighth of an inch of pad left, it's time to replace them. And when the pads get replaced, the rotors should be replaced, too. Since you can't measure them yourself, you're going to have to trust a mechanic.
If you really believe the dealer is trying to push unnecessary repairs because he doesn't have enough cars to sell, you can always go to a shop that doesn't sell cars and get a second opinion. But by any measure, you've done well to get 74,000 miles out of a set of brakes. So, even if you don't need new ones right now, it's not too early to start shopping around for a set of brake pads in a color you like.
Even if your old car doesn't start, it can start conversations that will help all of us learn more about the world. Donate your old car to your favorite NPR station. Here's how.