If Trevor's contention is
If Trevor's contention is accurate, I would be curious how adaptive he's suggesting the Eco is? Can you continue to get more aggressive engine performance well beyond 93, simply because the engine adjusts for it?
If it benefits from premium its because 87 must be inadequate for maximum efficiency, not because the fuel contains more energy. If someone has the physics article that describes how I'm wrong and that 93 octane gas inherently has more energy I'd love to read it. I'm suggesting that if the Nav recommends premium then that is a product of changes to how the engine runs relative to previous Ecos, not just fuel.
And if that change in engine performance is as dynamic as Trevor suggests than will the engine detune itself also to compensate for lets say 84 octane?