These Reische 170thermostats are custom made with the same size diaphragm and bypass control as the OEM units. Proper bypass control means maximum efficiency from your cooling system. Each of these thermostats is modified by hand using only U.S. made parts and then quality inspected to ensure consistent opening temps.

Whether you are using an aftermarket radiator or not, this thermostat will provide the best possible heat dissipation from your setup and even deliver better overall performance than our competitor's 160 thermostats. We believe the 170 opening temp is the ideal balance for high performance engines, providing high flow to your radiator by mid-180 temps while still providing good all season performance. With proper fan settings your coolant temps in cool weather will be in the 170s and in hot weather the 180s, giving those running high levels of timing and/or boost added protection against engine-damaging detonation as well as maximum power output.

For 4.6L DOHC, transverse 3.5/3.7L DOHC & EcoBoost applications and also the 2005-2006 Mustang GT. All Reische Performance thermostats ship with a new gasket, coolant ratio/additive recommendations, fan settings for popular handheld programmers and are backed by a 5 YEAR WARRANTY.