Originally Posted By: nap
It’s matched to the TGDI engines fuel dilution, the average owner won’t notice anything.
True there. A 0w20 becomes a 0w16 really fast with fuel dilution. Now if you START with a 0w16 fresh, you might have a 0w10 after a few miles.
Maybe these fuel dilution issue with Hondas, Ecoboosts, others, might put the brakes on migrating to 0w16. Too thin to start with.
"Too thin" depends on bearing loading, you know, the pressure put on bearing surfaces. Widen the bearing, then you can use thinner oils. The engineers know where the wear threshold is. Experimental set-ups I've seen graphs for show a pretty sudden increase in wear at some point, depending on the engine, maybe HTHS=2.0 wear goes up a lot. I guess the engineers could get that to HTHS=1.8 or something by increasing bearing surface area (rings, journals, cam lobes, etc.).