The Mishimoto racing thermostat for the 99-05 Mazda Miata NB will promote greater cooling efficiency in your stock or modified Miata. Once the engine is fully warmed up, Mishimoto's Miata NB 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 99-05 Miata NB racing thermostat is the perfect addition to your street or track Miata and is a direct replacement for the stock thermostat. This thermostat includes the signature Mishimoto Lifetime Warranty.