The only downside was that the old thermostats I saw and replaced had gaskets that lay between the thermostat housing and the engine. Newer ones like these now have a rubberized ring that wraps around the widest part of the thermostat and fits into the thermostat housing, eliminating the need for a gasket. Unfortunately the ring on the thermostat that I replaced is worn and unusable and the new ring was not included with this purchase. A bit of a disappointment and irritation when I had to go to an auto parts store and spend $5 on a new ring. Just a rubber ring? $5? Hell, the thermostat is only $5 or so. uh, live and learn.