The Air Intake Pre-Heater Hose is used to warm up the air that enters the engine, which can improve fuel efficiency and reduce emissions. 

It is particularly useful in cold weather conditions, as cold air can cause the engine to run less efficiently. By warming up the air before it enters the engine, the Air Intake Pre-Heater Hose can help to ensure that the engine runs smoothly and efficiently, which can ultimately lead to better performance and lower fuel costs.