20,000 miles is not a typo... that's how long the rear pads usually lasts... anywhere between 20k to 30k... and no... it's not the old lady syndrome... the brake pads all around on my Lexus RX300 lasted 85k miles... it's the weight of the ML and also the compound used in the ML Also, depends on how much city driving and how much highway driving... if you drive in traffic a lot... that affects the wear on brake pads... by the way, the rear brake pad don't wear evenly, usually one of the pad wears out a little quicker... that's why sometimes you have to replace them early.