I don't know if it's just me or what, but I usually drive long distance, say 6-8 hours regularly, in hot M'sian weather, as we all know it.
From my observation, if I'm using 30 weight oil, doesn't matter if it's mineral 10W-30 or semi/full synthetic 5W-30, as per recommended in the manual, during those long hours of driving, I can hear the engine revving 'rough', like the engine was suffering screaming arrrghhhh or something like that, hahah.
I do understand about the recommendation of oil weight in relation to the engine's clearance, but out of geramness about the rough revving sound, I changed to Shell Helix Ultra 5W-40, and walla, even after hours of driving under the blazing sun, the engine feels & sounds smooth, no straining screaming rough revving, the engine was like: "chill brah, I'm good".
And on one trip with my friend who's driving the new 2019 Myvi, that was using the centre's 0W-20, man.., the engine sounded so rough for a new car, screaming like it was dying..
That was my experience btw, so in terms of engine's clearance vs ambient temperature, I think the SAE engine oil weight recommendation in relation to ambient temperature does holding some truth.