The breakthrough that was made to get the "fake" synthetic, which I am FAR less critical of, performance wise,
than Ian, was called hydrocracking. This was first done by a joint Conoco-Pennsoil pilot plant on the Texas coast. I
attended an SAE tech meeting where a Conoco engineer took a deep dive into the chemistry and the results. For
some time hydrocracked base stocks, which were petroleum that had been broken down into nearly identical short
chains from their random, original long branched chains, as pump out of the ground, was then reassembled
into nearly identical length longer chains (of carbons and hydrogens, why all this stuff is called "hydrocarbons")
which were pretty darned consistent in behavior. Only Conoco and Pennsoil sold these oils for a number of years.
I think I might actually have the Powerpoint slides around somewhere on an old computer.
Hydrocracked oils were ALMOST synthetic, and could, as Ian said, be made into lubricating oils that would
meet the same performance criteria as synthetics would meet. Ultimately, these hydrocracked "fake synthetics"
ARE way better lube oils than the best petroleum oils from the 70s and 80s, but not as perfectly made, basically
flaw-free chains that you get with the truly man-made from natural gas stuff. That is put together from CH4s....and
you get a long chain that is pretty much identical from molecule to molecule and has no "loose ends" which
will easily react with stuff, like oxygen or metals, to change the oil into guck. THAT makes it super stable with heat
and time. The hydrocracked "synthetics" don't go all the way back to CH4s, more like C8 or C10 or something in that
range, I forget exactly. And they DO have a few side branches and unterminated ends left over from their original
state which will react, or fracture under time and heat, etc. So, are hydrocracked 'synthetics' as long term stable under
heat, shear, and time as the made from methane synthetics? No, but for a lot of purposes they are pretty close, and
they are definitely a legitimate breakthru in performance, at a lower cost than the "real" synthetics.
I will use the hydrocracked oils in my cars, they are really good lubricating oils. BUT I do change them at about
50% of what the Honda computer recommends, and in my older vehicles about every 5 or 6K, where in the old
generation of oil, I went with 3K oil changes. And regardless how good your engine's base oil is, wear particles
are slowly turning it from lube into fine grinding compound over time, and that stuff is absolutely unfilterable
except with high speed centrifuges, which are impractical for vehicles, both cost and size. So, IMO, I do not
want to go 20K on ANY motor oil, even if the base oil is in great shape chemically because it is contaminated
with metallic wear particles, I want it OUT.
I am not a lube oil engineer, but I have met a few and spent some time listening and asking technical
engineering questions and I think I learned a few things from them. And my first job was with a huge chemicals
and plastics company, and I learned the rough basics of how all our various polymers are made, on an industrial
scale and designed and installed equipment to do it before I moved to aerospace.
But for greases which will need to not deteriorate over many years, the true synthetics are THE way to go.
Bill