A car should generally be serviced every 12 months or every 12,000 miles (approximately 19,000 kilometers), whichever comes first. Some cars may need an interim service every 6 months or 6,000 miles, depending on usage and manufacturer recommendations. Factors such as the car's age, type of driving (e.g., frequent short journeys or stop-start traffic), and specific manufacturer guidelines can influence these intervals. Most manufacturers advise a full service annually to maintain optimal performance, safety, and to avoid costly repairs. Modern vehicles may have onboard systems that alert when a service is needed. Regular servicing helps ensure the car runs efficiently, improves fuel consumption, and extends the vehicle's lifespan.