HKS Oil Cooler Kit - 23+ Civic Type R (FL5)

NOTE: Modification to the bumper and splash shield is required for installing the air ducts. Approx 0.5L additional oil required when installing oil cooler. Includes resin-molded air ducts, optional dry carbon air ducts sold separately.

Engineered for sustained high-load driving in +R Mode - HKS' advanced cooling approach optimized for the FL5. The ultimate oil cooler it for maximum thermal management performance.

Development Concept

• The Civic Type R FL5 has made significant advancements from its predecessor, the FK8-including improvements in handling performance, power output, and aerodynamics. However, through extensive road testing and durability evaluation, HKS has identified a key weakness: oil temperature tends to rise rapidly under high-load driving conditions.
• To address this, we have refined the proven cooling layout from the FK8, utilizing the left front fender location while redesigning the system to match the characteristics of the FL5. Considering coolant temperature and A/C performance, the oil cooler core has been positioned for maximum thermal efficiency.
• Wind tunnel testing confirmed that airflow from the OEM front bumper alone is insufficient for optimal cooling. Therefore, a newly developed large air duct and dedicated air guide were designed specifically for the FL5 to deliver a strong supply of fresh air directly to the oil cooler core. This maximizes the performance potential of the system.
• Not only air intake but also evacuation of heated air was fully optimized. Through repeated aerodynamic testing, we ensured smooth discharge of air after it passes through the core, achieving the ideal airflow balance for the complete system. An outlet plate is included to protect the core from rock damage. As a result, oil temperature rise is significantly reduced even under demanding environments such as circuit driving, allowing the FL5 to maintain stable peak performance over extended periods. (See data on the following page.)
• Two types of front ducts are available for installation on the front bumper:
  - Injection-molded duct (standard with kit) - High accuracy and cost-efficiency through mass-production molding. (Unpainted)
  - Pre-preg carbon fiber duct (optional) - Lightweight, high rigidity, and a premium appearance with a dry carbon finish. Each piece is handcrafted by skilled craftsmen. (Clear-coated with metal mesh installed)
  

Compared to the stock configuration, the installation of the oil cooler provides an approximate 15 Degrees C reduction in oil temperature. With an ambient temperature of 26 Degrees C, the oil temperature remains stable at around 125 Degrees C even during continuous high-load driving. In contrast, the stock system exceeds 140 Degrees C without reaching a stable temperature range. By positioning the core inside the left front wheel well area, which does not obstruct the radiator airflow, coolant temperature is also reduced by 3-5 Degrees C, allowing the engine to consistently deliver stable performance.

Kit Components

• Oil Cooler Core
• Air Duct (Unpainted)
• Air Intake Duct
• Core Protector
• Mounting Brackes
• #10 Oil Hoses
• Thermostat Housing
• Oil Filter
• Short Part (Fittings / Hardware)