No one said "200 is best", that would be as dumb as saying "160° is best", neither are necessarily true.
Application matters. Sure, if you're tuning for maximum power on a dyno or for a 1/4 mile, you probably want your temp closer to 160°. But in that case you're going from start to WOT to shut down again. You're not doing any real driving for any length of time and you can control the conditions.
Trying to tune your street car to run at 160° is flat out stupidity. Max power for WOT on a street car that's almost never at WOT? Dumb. Instead you want the engine to run better at lower RPM's, and you want all your gaps and tolerances right with the engine properly warmed up. That way you don't have to rebuild your engine every season.
And getting hyper focused on the coolant temperature totally forgets the fact that it's just the coolant temperature, not the combustion chamber temperature, or the block temperature, or the head temperature etc. A 20° swing on the coolant temperature (assuming it isn't boiling) doesn't mean much of anything to the combustion chamber temperature. It's important for drag racing because you're tying it to the air charge temperature, but that's only because of the short *** trip you're making. Drive for longer than a 1/4 mile and the intake manifold temperature is going to go up regardless, the engine compartment temperature is going to go up, and so the air charge is going to warm up no matter what you do. Pull over and ice it down! LOL.
So you know, maybe you should tune the car for the actual conditions it will be seeing? I wouldn't tune a strip car for 200°, and I wouldn't tune a street car for 160°.
