First of all It is misplaced faith to use uoa’s as a measure of lubricant performance for wear protection, deposit reduction or anything that is not a physical property such as flash point or viscosity. Second of all, don’t get wrapped up in marketing terms. Such as “intelligent molecules” or “deposit Shield”. It’s more likely a blending technician was explaining dispersant/detergent packages purpose to a marketing intern group on a plant tour and they quipped “ohh we could call it deposit shield!” That is more plausible than they have the corner on deposit control compared to other lubricants that and the designers insisted it have “deposit shield” in its name because of an extraordinary property.
Higher quality viscosity modifiers do more than help the lube resist thinning, they can also contribute to the lubes ability to suspend & disperse contaminants and keep deposits from forming. That will not show up on a UOA. That will not show up on a PDS. Only Chevron/Oronite knows this.
A lot of things don't appear on a VOA/UOA, like some esters are actually good solvents and capable of dissolving varnish. (im not saying Chevron uses esters, maybe they do... maybe they don't, you'd have to get them to disclose that)
How does Havoline Deposit Shield technology work? Is it actually a good thing or just marketing?
The truth is Havoline Deposit Shield Technology works through magic. Smart molecules so to say. How can any of the major oil brands be much different if they meet the same specs..
In some sense you're correct, buy a lube that meets the latest ILSAC, API and even better D1G2 and you're good to go...but keep in mind specs are minimum. And there's nothing preventing a mfg of exceeding specs. To that end, ROI and price points have to be considered.