More or less true. But this (cleaning) will not happen overnight. Nor with one tank. Or three. It will pay back when you are using the same fuel over many thousands of kilometres of highway/freeway driving. I speak from long experience, not some glossy marketing brochure. With SIDI engines, the benefits take longer to procure, because of their injection design as opposed to, for example, the Alloytec V6, which would be cleaned out thoroughly in 2 to 3,000km. This fundamental difference in engines does not in any way negate the value of using 95/98 (95 for Alloytecs 2005 onward, 98 for SIDI, 2009 onward) in SIDIs that certainly can benefit, but only if you are focused on improvement over the medium to long term. Nothing will happen in 24 hours of dreaming. It is the cherished preserve of enthusiasts who think 95/98 is a gimmick, because they have no understanding of how the engine will benefit going forward, instead they are disappointed and aggrieved to pay that much extra and not get the dreamed-of 100rwkw increase in power, grunt, snort and wank factor from the first tank, and nothing after that!! Takeaway: 95/98 is a long term commitment.
