PRL Motorsports Baffled Coolant Expansion Tank – Honda Civic incl. Type R FK8 / FL5

Upgrade your cooling system and engine bay with the PRL Aluminium Coolant Expansion Tank for the 2023+ Honda Civic Type R FL5.

Over time, factory plastic expansion tanks can weaken and fail due to heat and pressure cycles. PRL’s high-capacity replacement tank solves this by using robust 3mm thick 6061 aluminium construction that withstands extreme temperatures and higher pressures, delivering long-term durability and performance.

This upgraded tank more than doubles coolant capacity—1.32 quarts (1.25 litres) vs the factory 0.58 quarts (0.55 litres)—increasing thermal efficiency and reducing the risk of overheating under high-stress driving. Internal baffling minimises coolant slosh and cavitation, while the anodised finish and laser-engraved PRL logo give your engine bay a refined, motorsport-inspired look.

The kit includes all required fittings to suit multiple Honda platforms including the FL5, FK8, DE5, and 10th gen 1.5T Civics.

• More than 2x the coolant capacity vs OEM tank
• 3mm 6061 aluminium construction – laser cut and TIG welded
• Black or red anodised finish with laser-etched logos
• Internal baffling prevents coolant slosh and cavitation
• Billet machined barb fittings and 10AN sight glass
• Buna-N O-rings for superior heat and leak resistance
• Complete drop-in kit with all necessary fittings included

Kit Includes:

• (1) Fully welded and anodised expansion tank (black or red)
• (1) 1/16” NPT to 8mm barb fitting
• (2) 8AN ORB to 14mm barb fittings
• (1) 8AN ORB to 17mm barb fitting
• (1) 8AN ORB to 8mm barb fitting
• (1) 10AN sight glass

Vehicle Fitment:
Honda Civic Type R FL5 (2023+)
Honda Civic Type R FK8 (17-21)

Installation:
Click here to view the installation instructions (PDF)