CSF 3943 Radiator

OE-Style Radiator Upgrade for Toyota and Lexus

CSF Part Number 3943 is an OE-style radiator built with an aluminum core and plastic tanks for direct replacement cooling performance. It is engineered with a higher-performance, stronger B-tube design and is compatible with select Toyota Corolla, Prius, Prius Prime, and Lexus UX hybrid applications.

Key Features

• Aluminum core with plastic tank construction
• Cross-flow radiator design
• 5/8 in. core thickness
• Core dimensions: 26 9/16 in. length and 14 5/16 in. width
• 1 3/8 in. inlet on the right side and 1 3/8 in. outlet on the left side
• Single-row core layout
• OE-style fitment with upgraded B-tube construction
• CSF Part Number 3943

Detailed Description

CSF 3943 is designed as a direct-fit radiator for hybrid and compact Toyota and Lexus platforms, including the 2021-2022 Toyota Corolla, 2020-2022 Toyota Prius, 2021-2022 Toyota Prius Prime, 2020-2024 Lexus UX250h, and 2025 Lexus UX300h. The radiator uses an aluminum core paired with plastic tanks in a cross-flow layout, matching OE-style packaging while adding a stronger B-tube core design for improved cooling efficiency. CSF manufactures a wide range of radiator applications and validates cooling performance through laboratory wind-tunnel testing, supporting consistent thermal management across daily driving and stop-and-go use. This part cross-references BBB Industries 13922 for the same application.

What This Radiator Helps Address

• Overheating caused by a leaking or restricted radiator
• Coolant loss from cracked plastic tanks or aged core seams
• Reduced cooling efficiency in hybrid commuter driving
• Temperature instability from a damaged or corroded OE radiator
• Replacement needs after collision or front-end cooling system damage

Installation Notes and Tips

Verify inlet and outlet orientation before installation: this radiator uses a 1 3/8 in. right-side inlet and 1 3/8 in. left-side outlet. Confirm vehicle-specific fitment for your Toyota Corolla, Prius, Prius Prime, or Lexus UX application before removal of the original unit. The radiator cap is not supplied, and no oil cooler is included.

Quality Assurance

CSF radiators are manufactured in ISO/TSO-certified facilities and are engineered to meet high-performance standards. The brand has supplied radiators worldwide for more than 50 years and produces a broad catalog of radiator applications for major vehicle platforms.