Originally Posted by
dedwards0323
What one needs to remember regarding additives in motor oil is, if you are using a Multi-Grade motor oil (which most of us use nowadays), the oil already has a polymeric additive typically referred to as a Viscosity Index Improver (VII). These help sustain the viscosity of the oil over the typical temperature range the oil would experience. There really is no need to add another oil additive to these motor oils. Single-Grade motor oils could possibly benefit from an oil additive, but typically these grades were used in older model engines & oil change intervals were recommended by OEMs as being between 3000 & 5000 miles. It would be unusual for these oils to degrade enough to require a "boost" from an oil additive as long as the recommended oil change interval was being adhered to. And over the years, there have been significant improvements in engine design and motor oil formulation (my 1968 Mustang Fastback didn't have synthetic motor oil available to use) such that today's OEM recommendations typically don't reference additional oil additives. Like others before me, I don't add any additional oil products to the engines in my cars.
I agree with essentially all of this. In fact, I attribute the advent of technology's role in the formulation of modern synthetic oil to why I not longer preach heavy (40 and 50 weight) motor oils. Back in the 70's and 80's, I used 15W40, 20W50 and even 30 or 40 weight oils in most all engines. Back then, I never would have envisioned putting 5 or 0 weight oil in an engine! But today, all the motor oils I use are 5W40 (Crossfire) or 10W40 (Ford Ranger).
Today, the products we are putting in our engines are, I believe, superior to what we had 40 or 50 years ago. Dave, (180) would you agree?