The Mishimoto racing thermostat for the 97-01 Audi A4 1.8T / 00-06 TT 1.8T/3.2L will promote greater cooling efficiency in your stock or modified A4/TT. Once the engine is fully warmed up, Mishimoto's Volkswagen/Audi A4/TT racing thermostat will open at a lower temperature than standard thermostats. This allows coolant to flow through the engine sooner, which reduces and maintains cooler engine temperatures. The Mishimoto 97-01 Audi A4 1.8T / 00-06 TT 1.8T/3.2L racing thermostat is the perfect addition to your street or track A4/TT and is a direct replacement for the stock thermostat. This thermostat includes the signature Mishimoto Lifetime Warranty.