I been fairly lucky with Walmart so far. Had one gallon missing out of a 15w40 3 pack and they just refunded me the cost. Kept the two. Other than that it's been perfect.
Anyway .
12 qts Amsoil 10w40 Small Engine
4 qts Amsoil DCT
4 qts Amsoil Metric 15w50
I got a year on my 23 Santa Fe 2.5 turbo. But it's not short tripped. The new Mazda CX30 turbo I bought seems to be worse on the oil. It's driven much more and only short trips would be from moving it away from trees during storms or to wash it. I'll have to get a uoa next change and see how...
Just mention the viscosities as they don't make a 5w30 in it which was being discussed. The 10w30 would likely do fine. Anything besides the stock called for 20w would be an improvement.
The 2.5s have been reliable overall. Hyundai has had some fuel injector quality issues and I assume Kia has as well. Dct in the turbos are still occasionally failing but that's gone for 26.
I'd keeping using the AMSOIL Premium Protection 20w50. Your trying to fix an issue you yourself admits does not exist which is burning oil. Why not use what's been working good for you?
Something about esters not playing nice with hbnr belts. Don't see it being an issue myself. Timing chain in the 3.0 has historically been a far bigger issue with lm2 and even the upgraded one in the lzo.