HKS S-Type Oil Cooler Kit – Subaru WRX STI VAB (2015–2021)

The HKS Oil Cooler Kit for the Subaru WRX STI VAB is designed to stabilise engine oil temperatures during continuous high-load and circuit driving. The FA20 turbo engine produces significant heat, and the factory system can struggle to maintain safe operating temperatures. This kit delivers reliable oil cooling performance to protect the engine and maintain consistent power.

Concept & Features

A 48mm-thick high-efficiency oil cooler core is mounted on the driver-side fender area. A dedicated air duct channels fresh air straight through the core and vents the hot air out through openings in the wheel arch, ensuring stable cooling even under extended high-temperature operation.

Despite its fender-mounted layout, the kit retains compatibility with the factory fog lamps. This makes it suitable for both street and track use where maintaining OEM functionality is preferred.

• 48mm thick high-capacity oil cooler core
• Dedicated air duct for efficient airflow management
• Hot air exits through wheel-arch vents for stable cooling
• Fog lamps remain usable with the kit installed
• Designed for continuous high-load and circuit driving

Installation Notes

• Requires modification of the mud guard, under cover, front bumper, air cleaner, horn bracket, and exhaust manifold heat insulator
• Prepare 5.5L of engine oil for installation

Included in the Kit

• 48mm oil cooler core
• Vehicle-specific air duct
• Oil cooler hoses
• Mounting brackets
• Hardware set

Installation Manual

Download HKS Install Manual (15004-AF111)