When I know I have a cold, I have some zinc lozenges that I start taking. IMO and many others agree that the zinc can change the blood just enough so the cold critters do not hang around as long. Well how many know and then understand how zinc and more importantly zinc dialkyldithiophosphate is relative to engine wear? Now I am not selling Zinc Additives but below are some cams that reflect premature lobe wear. In the US, the EPA mandated that the levels of zinc dialkyldithiophosphate, ZDDP, be reduced. ZDDP helps lubricate at engine start up. Older model cars have more of an issue but even our MINIs can incur this issue as demonstrated by the picture below. Higher level of ZDDP will affect the catalytic converter and all of us here would NEVER remove our cats. Here are some good articles on this issue. https://www.hemmings.com/blog/2012/10/18/tech-101-zinc-in-oil-and-its-effects-on-older-engines/ https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=889147 Read them, become informed and make your own decision.
And dont forget to change the oil !! Todays oil doesn't 'break down' as fast as the older conventional oils , but it does get dirty !! Oil and filter every 10 K is good !!
Yup, I still change my oil ever 3,000 because oil is very cheap insurance/ protection over expensive engine parts. This is especially true when running Meth as the oil gets dirty quicker and the meth breaks down the oil faster. Also, I am not a believer is long life oil changes because no matter what oil you use it is still only being filtered with a old school paper filter. Once the filter is dirty and full of gunk it can’t filter or hold anymore stuff so it stays in your oil washing around in your motor and that’s never any good. As far as zink ZDDP for cams is great and one of the best oils you can use in a new motor, head, cam is Joe Gibbs Driven BR Break-In Motor Oil https://www.summitracing.com/search/product-line/joe-gibbs-driven-br-break-in-motor-oil