Fits Audi A4 B6 1.8 T Quattro Genuine NRF Engine Cooling Radiator Fan. We apologise in advance for any inconvenience caused. NRF radiator fans are designed for the latest technologies.Extensive (vibration) tests ensure an excellent performance and durability. NRF offers the largest range of radiator fans (cooling fans) for the Automotive aftermarket. More than 600 unique cooling fans perfectly fit popular passenger cars and light commercial vehicles. With a total car park coverage of nearly 75%, NRF is on track to reach the goal of a 90% coverage. The radiator fan has an important job in the engine compartment. It helps to regulate the engine temperature by pull (or push) air through the radiator core. During normal operation, the forward motion of a vehicle forces air into the front grill and through the radiator. This airflow can account for as much as 95 percent of the actual cooling that a radiator performs. When a vehicle isn't moving, and under heavy load stresses, a cooling fan provides the extra airflow that can prevent an engine from overheating.