Machining tolerances in today’s manufacturing has gotten ridiculously good. That and everyone trying to achieve better mileage numbers. I’ve fixed several vehicles that folks brought to me that ran like crap due to improper oil weights. First one guy said started after I changed the oil. He put straight 50wt in a engine designed for 0w20. Oil was too thick for the variable cam timing to work right. Not saying you couldn’t run say 10w30 in place of 0w20 but just know if it designed for light oil I’d probably stay on the lighter side.