They perform better in NVH tests, meaning they’re less susceptible to judder and screeching. Geomet Coated Discs:Spring showers, humid summers, and cold, wet and icy winters – they can all take their toll on your vehicle. Factors such as rain, snow, salt and other road sprays can result in corrosion. That means, exposed parts, such as brake discs can quickly become rusty – not a good look when you want to.