21 F-150 Ecoboost towing oil grade

There’s something to this, I think, meep… if you look at the 0/5W oils, as VI increases, so does Noack. We’re told high VI is very desirable, but when we look at the 10/15Ws we generally see much “worse” VI, yet UOAs show they are more shear stable, with very low Noack (some 5% or less!).

Also, when we look at many of the engines with heavy varnish, sludge, or phaser/timing chain issues- we see the OEM oil specs usually steer the user toward higher VI oils, especially when cold weather is involved.

Question: is the CAFE push and the “improved” formulation with high VI additives really just a planned self-destruction/continued service requirement? Like, with all these things lining up, intake valve cleanings & timing chain & phaser failures that seem to be improved by an “inferior” VI oil due to lower shear & Noack, can’t we seriously ask that question of oil blending experts?

I know no oil will stop engineering, machining, or materials defects, but all the signs make me wonder: if you ran an engine that called for a 0/5W30 instead on a 10W30 or even 15W30 (if it existed, of course) for a half-million miles, would there be statistically measurable wear and failure rate differences by sacrificing a few tenths of MPG while the engine was cold? I need an adult beverage now! 🤣
RIGHT? If I go with a 5-X oil, then it’s a 5 weight oil plus viscosity improvers spanning the gap. If I start with a 10-X oil, there’s less reliance on VI. Or in simple terms, less VI, more oil.… sturdier result. I ran into this in a honda mower that suffered damage with a 5-30 in high heat, high load conditions, and stopped getting worse when I moved to a 10-30, same brand.

i studied those trade offs years ago here, long enough to decide on the path, change my thinking, and move on. I’ve forgotten all the details but it’s served me well. I do the same thing with my son’s civic 6mt 1.5T, and i simply haven’t had the complaints folks discuss with that engine after it hit about 20,000 miles and we soldier on. I like going with a higher low number in general to reduce the spread. (Exception 5-40 castrol seems to be the CATS MEOW for Volvo 2.4Ts. Why did it have to be that one?)

something else that’s probably helped is simply just listening. Be patient with the machine, listen to it, make adjustments to what seems to give the best results. this won’t work for someone who has to fix 5 of them every day, but as my own - you kinda get a feel for it through the seasons?

I settled on 10-30 full synthetic and change when the OLM goes off. I’m ok with it because there is 0 difference in sound before and after.
Keep in mind, there won't be any sound associated with a high level of circulating particulates and evaporated fuel byproducts (the reason oil is changed). Just a higher timing chain rate of wear. A high quality 10W-30 may help with this somewhat, being a little closer to the ideal viscosity for chain lubrication. I stick with 5000 mile OCI's on my EB engines.
Confused yet?
Everybody has a different idea of what's best and I suspect none of them are "wrong".
On my 2.7, I had an analysis done a while back (Oil Analyzers) which led me to a use a 7500 mile interval with Motorcraft semi/syn. I've since tried some full synthetic (Pennzoil is in it at this time). Is it better? Probably not enough to make a difference where you could ever tell.
I will add that the highest mileage Ecoboost I'm aware of made it to 465,000 miles before the transmission died. 2016 2.7 that lived on Motorcraft semi/syn, changed when the dashboard said to. That works out to every 10,000 miles.