This depends on a number of factors, such as your car model, manufacturer’s instructions, the fuel injector, and the fuel system cleaner you use. In general, new cars don’t need regular fuel cleaning. The older the car gets, the more cleaning it requires. As you cover more miles with your vehicle, the fuel system and internal components will start to experience carbon buildup. The engine of your car will also start to lose its efficiency. Experts recommend fuel system cleaning once your vehicle has covered 30,000 miles. If you have an older vehicle, then you may need frequent cleaning. How often you need fuel injector cleaning also depends on your goals. If you need a basic cleaning to fix some minor problems in your engine, then consider cleaning the fuel system every 4-6 months.