The Automotive XL r is a durable, heavy-duty replacement V-belt designed for the most demanding engine drives. Due to thermal forces in the vehicle engine, this variable notched belt tightens on the drive as it heats up to prevent slippage or belt loss, improve belt performance, and reduce noise. Fiber-loaded rubber stock adds flexibility along the length of the belt and provides greater lateral stability in the pulley. Form-ground to ensure precise top width and sidewall dimensional control for proper fit to the pulley. Thermally active tensile cords for maintenance-free performance when properly installed and tensioned. XL Belts resist oil, heat, ozone, weather, and aging for improved belt life. Meets or exceeds SAE J636C specifications.