Drum & Disc Brake Tech - Whoa, Whoa, Whoa! Photo Gallery
The rotor on the right is a low-cost, non-vented production Ford Explorer brake rotor. In contrast, all performance brake rotors and most medium-duty or higher-performance OE rotors are vented (arrow). A vented rotor is basically a rotor with two surfaces joined by vents cast between the rotor that provides a larger area to dissipate heat and a path to exhaust the heat. Vented rotors have been in use on most production Chevrolets since the '60s and earlier on some other makes. Typically, smaller cars use non-vented rotors.