PRL Motorsports | Baffled Coolant Expansion Tank | Honda Civic Type R | FK8/FL5 2.0T K20C1 | 2017+Over time, the factory plastic coolant expansion tanks that Honda Acura include from the factory can weaken and fail from heat and pressure cycles. The PRL Coolant Expansion Tank kit replaces the factory tank with a more robust aluminium version. PRL's 6061 aluminium tank will not be effected by temperature and can hold higher pressures so it will out last the factory tank. This reservoir also more than doubles the tank's coolant capacity to 1. 32