high water temp?

[cnavarro]

Yes, the thermostats are designed to cycle. The low temp thermostat doesn't start to open until 160F (hence why it's called a 160F thermostat) whereas the factory ones doesn't open until 186F. There is no meaningful difference in warm up nor in heat to the cabin (ran one most of winter here in Chicago even on sub zero days and no engine codes either, which other users have also confirmed with me on their cars with the 160F thermostat. The low temp T-stat has full flow by around 175F (give or take a few degrees) where the factory one doesn't until around 200F. I tested a handful of factory thermostats and some didn't fully open until 205 or even 210F, which was very scary.

The thermostat will cycle closed if there is too much cooling capacity, but you really don't see this unless outside ambient temps are under 50F (which I've observed with data logging with a momentary drop of coolant temps to 166F, then it rises about 10F before settling back at 172F).

It's a given, in traffic, without sufficient air flow, the low temperature thermostat cannot take advantage of cooling capacity of the radiators. In motion or on the track, that's completely different scenario, where the low temp thermostat, especially at higher rpms with lots of coolant flow, keeps the engine well below the temperature that an engine with a stock t-stat runs.

Lots of people also don't equate coolant temp to oil temp, as these engines use laminar flow oil to water heat exchangers. A 15-20F drop in temp is a big deal to oil temperatures, which in my own testing, are usually about 10F above the coolant temp in normal driving and in hard driving, upwards of 20+F over coolant temp. This is huge!