There are three main types of filters used in most generators — the air filter, fuel filter, and oil (lube) filter. The air filter cleans the air before it enters the engine, preventing dust and debris from damaging internal components. The fuel filter removes impurities and water from the fuel system, ensuring clean combustion and protecting injectors. The oil filter keeps the engine oil free from dirt and metal particles, maintaining smooth operation and prolonging engine life. When choosing replacement filters, it’s important to match the exact part number and specifications recommended by the generator or engine manufacturer. Each filter varies in size, thread, and filtration capacity depending on the engine type (for example, Perkins, Cummins, or Kirloskar). Always verify whether your generator requires a primary and secondary filter, as some models use both for finer protection.