刹车片厚度小于1/8 inch / 3.2mm（不包括铁板）是非换不可的充分必要条件，生锈不是理由。
What is the minimum thickness for disc brake pads? Replace your brake pads if they are under 1⁄4 inch (6.4 mm) thick. A new brake pad is usually around 1⁄2 inch (13 mm) thick. Brake pads that are 1⁄8 inch (3.2 mm) thick should be immediately replaced and aren't safe to drive on.
我一直都是在车行保养换车胎，今年保养说刹车片生锈了要换，6百多，这么贵！过一两年我准备换车了，冬天开要换吗？
What is the minimum thickness for disc brake pads? Replace your brake pads if they are under 1⁄4 inch (6.4 mm) thick. A new brake pad is usually around 1⁄2 inch (13 mm) thick. Brake pads that are 1⁄8 inch (3.2 mm) thick should be immediately replaced and aren't safe to drive on.
去年dealer说只剩3mm了，问俺换不换？No,要换也自个儿换，一年之后开过了8796迈之后的今天还是3mm的样子，不到brake wear indicator 的铁皮蹭上rotor俺都不会换。
踩上两脚刹车就立马光亮如镜。
人家一定爱死你了。
不单是钱的问题，是人家保证你的车能达到原厂出厂标准！
WTF原厂出厂标准。