Basically what I have learned through the years, is if the engine won't stay cool at all times, highway, city traffic or idling for an hour straight, while running the factory t-stat (usually 195*) there is something wrong with the cooling system.
I drove my brothers Ford Taurus for awhile as work related transportation, driving around inspecting foreclosed homes, that engine would heat up while running the AC if I idled too long or just didn't drive enough, electric fans running constantly, still heated up... Ended up needing a new radiator, and being that it's an Arizona car, we tossed in a severe duty radiator,,, Maxi-cool is what they called it, basically wider cooling tubes, still two rows but equivalant to a standard 3-row unit. Never heated up again.
Same with the '94 pick-up, another 2-row Maxi-cool unit, heavy duty fan clutch, can sit & idle all day long in 120* weather, with the AC blowing and never go above the 195* t-stat, this is also the way my Burb is setup except it has a full on 4-row radiator with a heavy duty fan clutch.
My old '89 IROC used to get hot, replaced the electric fan switch controller to a lower setting, from the factory 205* down to a 190* and it stayed running cooler, that was a weird one though, it seemed that once it got to a certain point of "HOT" it just kept climbing in temperature faster,, new switch, fans kicked on alittle earlier, stayed around the t-stat or slightly higher, but nothing dangerously high,,never got around to putting a bigger radiator in that one, was traded off for the Burb.
I tried once installing a 180* t-stat in the Camaro, I did notice alittle more performance out of it, but also as mentioned, it used more gas doing this so it was pretty much a trade-off.
Had a few carb'd engines in the past, they didn't mind the 195 t-stats, but seemed to run better on a 180, again this may be due to climate though, like mentioned, it gets hot here so air intake is already pretty warm, 160's were always too cold, even in this hot climate during summer, even the mild winters, I still had no heat from the heater running one. Haven't bought one in 20 some years.
Anyway, I guess I'm just saying, that in the years I have been tinkering with vehicles, troubleshooting cooling issues and whatnot, I think I just finally got tired of screwing around with "standard" stuff here in Arizona's extreme heated summers, and go bigger when it comes to cooling, but keeping the factory 195* t-stats, they always work right as long as everything else in the system is working right.
this post turned into a Fordum post..
