2013/14 2.5i-L CVT
Um...yes, all.No not at all...
Sure, it helped them destroy the catalytic converters. If oil companies reduced or removed additives to protect the converters and drivers added them back with Rislone then that has to be the outcome unless you have some evidence Rislone's additives have some special protective properties the oil companies' additives don't. Not that it matters because whatever the impact Rislone may have on diesel engines says nothing about its efficacy in petrol/gasoline engines.Im simply saying that Riselone in particular is not snake oil... And that in particular it actually as helped the diesel owners community since the mandated change to the new CK4 type oils in the diesel industry.
Is it snakeoil. I don't know, but I suspect it probably is. Oil companies spend millions on research to optimize their products and one of the issues they have to deal with is trade-offs between an additive's gains and losses as with your diesel example. If extra additives enhanced engine protection without doing harm then why wouldn't the oil companies add them? The extra cost is likely to be minimal.