A vehicle’s oil life percentage is an estimate of the remaining useful life of the engine oil. This percentage, often displayed on the vehicle’s dashboard, is calculated by the vehicle’s computer based on factors such as mileage, engine operating conditions, and time since the last oil change. An oil life reading of 20% indicates that the oil is nearing the end of its service life and a change is recommended soon. It does not represent a precise mileage countdown. One vehicle might display 20% oil life with 1,500 miles remaining until the recommended change, while another might show 20% with only 500 miles left.
Regular oil changes are essential for maintaining engine health and performance. Engine oil lubricates moving parts, reduces friction and wear, helps cool the engine, and removes contaminants. As oil ages, it degrades, losing its viscosity and effectiveness. Continuing to drive with significantly depleted oil life can lead to increased engine wear, reduced fuel efficiency, and potentially catastrophic engine damage. Monitoring this percentage and adhering to the manufacturer’s recommended oil change intervals are crucial preventative maintenance practices. Historically, oil changes were based on fixed mileage intervals, but modern vehicles often utilize more sophisticated algorithms to provide a more accurate assessment of oil life based on actual driving conditions.