The average lifespan of a timing belt is usually between 60,000 and 100,000 miles, although some vehicles specify shorter or longer intervals. Always use the maintenance schedule for the specific year, make, model, and engine of your vehicle because the interval is based on that engine's design. Time matters too. A low-mileage vehicle can still need a timing belt if the belt is old, because rubber hardens, cracks, and loses strength from heat cycles, age, and oil contamination. Many auto repair shops treat seven to ten years as a practical age window for starting replacement planning, even when mileage is low. Severe driving, oil and coolant leaks, and failed tensioners can shorten belt life, so service records and inspections matter for overall reliability, resale value, and safety.