This product is specifically designed for the BYD472QA 1.5L Xiaoyun plug-in hybrid专用engine in the BYD Qin PLUS DM-i. It is a critical rubber hose connecting the radiator to the engine cooling system—the upper radiator hose (also known as the engine coolant inlet hose). As the "artery" of coolant circulation, the upper radiator hose is one of the largest-diameter, highest-flow, and most demanding hoses in the cooling system. It delivers low-temperature coolant from the radiator to the engine water jacket, where it absorbs combustion heat before returning to the radiator via the lower hose, forming a complete large-cycle cooling path to maintain the engine within its optimal operating temperature range (typically 80-105℃).

The Xiaoyun 1.5L naturally aspirated engine in the BYD Qin PLUS DM-i features Atkinson cycle operation with an ultra-high compression ratio of 15.5:1 and a maximum thermal efficiency exceeding 43%. The engine adopts split cooling thermal management technology (cylinder head and block separation design with dual thermostats), with independent hoses leading to the head and block respectively. The upper radiator hose is one of the largest-diameter, highest-pressure, and highest-flow core channels in the cooling system, and its reliability directly affects engine heat dissipation efficiency and overall vehicle thermal management performance. The DM-i hybrid system simultaneously needs to dissipate heat for the engine, electric motor, and battery pack, with the cooling system operating continuously under high loads, placing higher demands on the upper hose's heat resistance, pressure resistance, and aging resistance.

As a professional automotive cooling system parts manufacturer, we develop and produce strictly according to BYD OEM technical standards. Using a three-layer composite structure of EPDM inner layer + high-strength fiber braid reinforcement + weather-resistant EPDM outer layer, the product offers excellent heat resistance (-40°C to +120°C), coolant corrosion resistance, ozone aging resistance, and pulse pressure resistance. The product passes rigorous high-low temperature cycle tests and pressure pulse tests, with OE numbers precisely matching the original vehicle for direct replacement of aged or damaged upper radiator hoses, restoring proper cooling system operation.