i remember one article where it says "standard" size car needs only 10kw power on flat road to keep same speed ~45mph.
in other words; to make work all horses together, u need to keep accelerating hard (pedal to metal).
In the wife's Elantra for 5w-20 it was Magnatec, 10 decibels quieter than PP on my cheap meter, and for 5w-30 it's QSFS.
My older 98 Tahoe was by far the smoothest/quietist on RGT 5w-30.
The X5 had no change between TPT 5w-30 and QSFS 5w-40.
Mustang GT doesn't seem to care.