I watched a video on YouTube from a channel called Hackaweek and he built a 1973 CB750 from the ground up. When putting oil in he went with Rotella T stating that it had Zinc in it and is good for the old engines.
Is this why you guys like to use it so much and does the new formula still contain Zinc in it?
Automotive oils DO have Zinc in them.
The issue is how much.
Just within the Mobil 1 range, the ppm level of Zinc varies from 750 to 1300 within the street oils, up to 1850 in the racing oils, and up to 1750 in the motorcycle oils.
This from September 2014 data I have handy, and I don't think anything has changed since.
Phosphorous is a catalytic contaminant, yet all the Mobil 1 oils have it as well. Those ppm numbers are in league with the zinc numbers, but always lower. Then there is the Phosphorous Retention characteristic of the oil, as in staying in it, versus coming out of it - which is how the catalyst downstream in the exhaust system actually gets any phosphorous contamination.
T6 is really good stuff for bikes, the previous generation T6 5W40 JASO MA that is.
I haven't researched the new generation T6 0W40 as Canadian Tire still stocks the older stuff as well. They keep both on the shelf.
Back to Zinc again, more precisely ZDDP. If you want some, go to your GM dealer and get P/N 992704 ACDelco Camshaft and Lifter Prelube. An old engine builders secret assembly lube sauce for all but cylinder related parts was a 50/50 mix of 992704 and the engine oil to be used.