I never said one thing about timing chain wear.
I never said one thing about wanting to still use SN rated oils.
I never said one thing about price being related to oil specs.
My original post is simply asking what, if any, benefit there is in using more expensive oils in older cars, when a less expensive modern oil still exceeds what that engine was designed for. My posts have never strayed from that. Everyone else was inserting comments that had nothing to do with the original question.
YES, YES, YES.
1. Availability. Try finding SJ oil anywhere. I doubt it's possible outside of 2nd hand markets, in which the oil is 2 decades old.
2. Cost. Esoteric SJ oil is probably going to cost MORE THAN a premium modern backward compatible synthetic. It's probably no longer produced and would be viewed as either garbage, or a collectable! Garbage = free and collectable = premium money; either way a bit time investment locating it.
3. Time wasting. Searching high and low for SJ oil is a fools errand. Good luck.
4. While oil probably doesn't spoil on the shelf in ideal circumstances, finding 2 decade old SJ oil on Ebay stored in unknown conditions is going to have a higher failure rate than walking into a auto parts retailer and buying a brand new jug of SP fully synthetic.
5. Backwards compatible. New API and oils are backward compatible and work in old engines.
6. Better engineered - additives that didn't exist or were not common are in modern oils that aid in all manner of cleaning, lubricating, bonding to dirt to suspend the dirt, longer life, higher heat soak capability, and so forth.
So, there you have it. Cost, availability, better product, more convenient, "newer" product and not using very old stock of unknown origin, and so forth.
There's some folks here, including me, using up old stock oil in old cars. I inspect each quart for separation and contamination before adding, and then do a short OCI or use it for a cleaning interval, very short OCI, etc.
Does this answer the question?