SpeedLab did some runs & experimented w/ a few combinations of intakes, unichip, even custom header on both Sky engine variants. Fuel type logging is always part of their recording.
I remember among the many posts having Mazda's top honcho, Steven Tan, chiming in. It is officially proclaimed that going beyond regular Shell fuel save will just be a waste of money....no gains. It's not about our engines performing better or failing w/ higher octane.
Why Shell? It has the Mazda nod & Shell assurance for fuel quality & consistency. With known smuggling & shady industry practices of filling up station tanks with generic, from-no1-knows-where, who-knows-what fuels, I'd go w/ what Mazda approves. Shell has color coded products. They strictly monitor retailers. These are just among their system checks, & are 1st hand accounts from buddies inside Shell.
I understand the doubts & cynicism but remember, SkyActiv has thrown combustion engine conventional thinking off.
It's your call, Yatta sir. By all means, carry on w/ those experiments. Knowledge has always been a product of curiosity. Please share whatever significant conclusions you may discover that SkyActiv engineers have yet to. This is all healthy exercise.
