I do not think anybody doubts that different base stocks have different costs.
Ester being the most expensive, followed by PAO, followed by GTL, other group 3-s,
group 2 and refined mineral oils. I would be surprised if a maker/blender
could pick a cheap base stock, and then turn this into something magical, "specially designed.."
for whatever purpose by just adding additives. A proprietary additive package to make up
for the shortcomings of a mediocre base stock is IMO lipstick on a pig.
Printing some words on the package costs 0$, and totally meaningless.
The biggest disadvantage of the inexpensive base stocks imo is thermal breakdown, sludge
formation and shearing down of the additives (mainly the viscosity index modifiers) .
Let's not forget the contaminants inherently present in the raw material (mostly aromatics)
which are both a health and environmental hazard.
The sort of "evidence" folks tend to post "my brother in law used ...inexpensive product..
in his application and never had oil related problems " is not useful. Anecdotal, unverifiable evidence.
Obvious oil related catastrophic engine problems rarely manifest over the typical lifetime of a consumer
engine, no matter what you do, as long as you avoid gross negligence. Modern engines are amazingly well made,
and can take a lot of abuse. But that does not mean that abuse is the best recipe for preserving your
engines long term. Which is one of my explicit goals.
I find it entertaining that people bother to post opinions like "hey I used an inexpensive
lubricant/filter whatever, and I did not suffer any obvious consequences. You should too, and save
yourself (gasp) $20 on each oil change!".
My reaction: "congratulations, you beat the system. Please mention your experience to a leming".
If the manufacturer was serious about producing something outstanding,
they would start with a high quality, premium base stock, to factor out the contaminants.
This is reason enough for me to I avoid any lubricant which is "lesser" than at least GTL based.
Gtl, group 4 and group 5 are all produced by chemical synthesis, thus entirely avoid the common
pollutants such as aromatics that can not be fully refined out of the "lesser" base stocks.
That makes sense to me.
And the price difference between a premium product and an economy product
at the consumer level is not enough to take a chance on.
Regarding mono-grade: Is there a synthetic monograde oil? Or that is a red herring because
the Group 3-5 base stocks inherently have a high VI, that just cannot be "undone"?