are you saying the coolant temp is the determining factor of how hot the whole engine gets?
No, that's not what I'm saying. I'm saying coolant temperature was a contributing factor in how the ECU performed its function and how cleanly and efficiently the engine will run and how it contributes to oil cleanliness, fuel economy, emissions, etc.
i have engines that i have only run vp c12 in because they were power added combos. you tear them down after 300 passes and the engines look like they were just assembled. absolutely zero carbon. and those engines never ran above 130* at the finish line. due to this it is my opinion that the fuel itself has more to do with carbon than engine temp.
A race engine running C12 fuel, WOT, for 1/4 of a mile at a time is not your average street engine. Running any engine WOT for any length of time is a sure fire way to burn away carbon...never mind one that spends the majority of it's life doing it. How many times have you changed the oil and filter throughout the course of those 300-passes? I'll bet several. That's less than 100-miles in total. Hardly what I would consider comparable to a daily driven street engine, running pump gas (now blended with ethanol) on a daily basis in all weather and driving conditions for several thousand miles between changes.
As you said....we're talking different uses here. For a primarily street driven vehicle, keeping coolant temps up to and consistent with recommended levels is always most beneficial. I'm not saying run it hot....but run it a recommended operating temperatures. Running below recommended levels generally shows little benefit with several negatives I’ve already noted.
i took your comment about the hot lapping at the track as road racing. my mistake. ill give you that they are more fuel efficient, i did say in a car that has zero performance use. as far picking up hp, there is a difference between what the dyno says and accelleration. if you made it run hotter with a given fuel, due to chamber/piston/cylinder temps you have to pull timing in order to keep the engine from preignition. that being the case i have NEVER seen a heat soaked accellerate faster than one that was cold. i think the disjunct here is we use our cars differently.
I wouldn't say stock coolant temperature levels are reserved for vehicles with zero performance use. Ever vehicle, of every variation rolling off the showroom floor over the last 25-years has maintained the same standard. Whether it's a 20-year-old 90hp Ford Escort, or a brand new 420hp Mustang GT. Pull the thermostat out and they're rated at the same 192-195F. They’re run at these levels because this is what’s required to meet EPA standards. They don’t just pull these numbers out of then air?
Heat soak, is heat soak no matter what you're running. You cool the vehicle between rounds to cool the entire engine down (primarily the intake manifold), not so much just the coolant levels. Running a track car with race gas built to run 1/4 at a time is one animal, bur in a street car...for that short time you're pulling up to the staging lanes, then blasting down the strip 1320ft, a 12-degree difference in thermostat opening temperatures isn't going to make a lick of difference in your ET''s. It’ll make more difference on the drive home that it will at any race track. At the track, It's not going to change your under hood radiant temps or the ambient air temperature any. You'll bet more benefit throwing a bag of ice on your intake manifold between rounds than you would swapping thermostats.
as far as your coyote comment, i dont see a lot of performance tuners making the car run HOTTER to make it run better. im sure increase in performance has nothing to do with piston speed, variable valve events, or cylinder head/induction improvements over the past 20 years.
My comment about the Coyote had nothing at all to do with coolant temps...or temperature at all for that matter. I was only addressing your statement that presumed to poor mileage and high performance had to go hand in hand with one and other.