Looks like the con rod specs not the mains. Post a pic of the page with that and the document headers. What would really prove the point is a current/updated main bearing selection chart, if the Gen2 and Gen3 Coyotes are like the Gen1. I don't see Ford deviating from this practice with production engines. It's a pretty slick system for decent factory tolerances, IMO.
How about this, I'll list the connecting rod big end and main bearing clearances along with other specs for the 2.3L Ecoboost, 3.7L V6 and 5.0L V8. I only have the specs for the 2015-2017's (2nd Gen). But I'll create another post listing the known differences between the 1st, 2nd and 3rd gen 5.0's (regular models, not special variants like the Boss 302's Road Runner for the GT350's Voodoo 5.2L FPC).
Please note that MOFT is higher regardless of how tight the clearance is. Even in a 0.0004 in clearance, according to King Bearings 10W-60 produces higher MOFT than 10W-30 and 10W-30 higher MOFT than 0W-5 regardless of clearance. However with tighter clearances the MOFT difference is extremely small where as with larger clearances MOFT is more linearly proportional (higher wights produce thicker films).
2015-2017 2.3L Ecoboost I4 GDI (OE Oil spec
5W-30)
Connecting rod bearing-to-crankshaft clearance: 0.0011 - 0.0020 in
Connecting rod side to side clearance: 0.1020 - 0.1453 in
Main bearing clearance: 0.0006 - 0.0018 in
Weight: 311 lbs without accessory drive components and flexplate
2015-2017 3.7L Duratec V6 (OE Oil spec
5W-20)
Connecting rod bearing-to-crankshaft clearance: 0.0008 - 0.0021 in
Connecting rod side to side clearance: 0.0069 - 0.0167 in
Main bearing clearance: 0.0010 - 0.0016 in
Weight: 355 lbs without accessory drive components
2015-2017 5.0L Ti-VCT V8 aka 2nd Gen Coyote (OE Oil spec
5W-20 for US & UK,
5W-30 for Australia)
Connecting rod bearing-to-crankshaft clearance: 0.0011 - 0.0027 in
Connecting rod side to side clearance: 0.0128 - 0.0197 in
Main bearing clearance: 0.0010 - 0.0030 in
Weight: 431 lbs without accessory drive components
2018-2019 2.3L Ecoboost I4 GDI (OE Oil spec
5W-30 and
5W-50 for Track Use)
2018-2019 5.0L Ti-VCT V8 aka 3rd Gen Coyote (OE Oil spec
5W-20 and
5W-30 for Track Use)
You can download the user manuals for 2015-2017 Mustang GT's 1st and 3rd revision for Australian versions. They changed the specification for oil viscosity from 5W-20 1st revision to 5W-30 3rd revision...obviously the car's ECU and internal clearances didn't magically change when they revised the user manual. This falls in line with what Steve said from Ford Performance, that you wouldn't be able to tell the difference between 5W-20 and 5W-30 on these engines and it will run fine on either. He even suggested it would be ok to use up to 5W-50 for track use.
It covers the same model year range...Australian Mustang GT's have the same rated 435 HP output and 400 ft-lbs torque same as the US versions, the engines are built in the same factory as the US and UK versions of the car. UK versions do get a tuned down ECU software to meet European emissions requirements and are right hand drive, so some of the hardware on the outside is different for the UK versions. However, the UK dealers actually refuse to honor warranty unless they run 5W-30. Over on the Mustastang6g forum there as everal guys from the UK that report the same thing. Likewise with the Germans.
I'll re-iterate that Ford Racing School 2015 PP GT instructor cars run Castrol Super Car 5W-50 on the stock ECU calibration. They don't touch the engine other than added cooling (19 row setrab air to oil cooler). Obviously they are after reliability under constant extreme use given the cars purpose as a training tool, not maximizing power output, but 5W-50 isn't hurting the car on the stock calibration despite the OE spec for 5W-20.
It's all about heat range. If you never sustain high RPM long enough to build up heat in the oil, thinner oils are fine. Maximizing performance is about using the thinnest oil that will provide adequate protection for the maximum heat range you expect. Track however typically generates extreme thermal loads so what is adequate or even ideal for street is often not adequate for track. So use a viscosity that can handle the thermal loads. Higher quality oils resist thinning and boil off, so you can get away with lower viscosity while providing roughly the same level of protection as a thicker but lower quality oil.