Mishimoto MMTS-RX8-04L Mazda RX8 Racing Thermostat, 2004-2010 Fits the 20042010 Mazda RX8 Lower activation temp allows coolant to flow through the engine earlier Maintains lower temperatures and extends engine life Mishimoto Activation: 169F (76C) / OEM Activation: 180F (82C) Mishimoto Lifetime Warranty