Coolant temp on any engine should not run over 200 degrees. As a certified auto tech of 51 years, I remember when we had 160 and 180 degree t-stats. When we saw over 200 it was a problem. With the new cheap plastic and aluminum component engines today high engine temps are even more problematic. Warpage and cracking is a common issue. Common sense dictates the cooler and more consistent the engine temp remains, the longer your engine lasts. In point, a 2012 dodge journey with a 3.6 pentastar v-6, (piece of pure garbage) runs normally around 220 degrees. These engines with less than 100,000 miles, regularly have had thermostat, water pump, radiator, oil cooler, water bypass housing, heater core, head gasket, cooling fan and more overheating problems. Not to mention cam phasers, camshaft, roller rocker, lifter, pulled head bolts and a multitude of other engine related issues. Why ? Running too hot with cheap Chinese plastic and inferior aluminum componants. High temp thermostats are a wet dream of some youngster engineer to insure you always have to have your engine repaired or even worse replaced. But then again, common sense in today's engineering is non existant. It's all about getting you to spend more money. Build an engine with USA made steel and aluminum, with a 180 degree two-star and watch it go 300 000 miles! Wow, what a concept! Just a note, my 1994 k2500 with 454 just cruised over 355,000 miles. It's never even had the valve covers off, let alone any overheating, with a 180 thermostat. Oh, by the way, it also runs a whipple supercharger and has towed most of its life. Well, enough common sense for now.