I personally stick to the recommendation of Honda. If I noticed a difference I would buy higher octane gas. I think 4 cylinder cars or cars that are pinging on lower octane gas would benefit. Just dont use unknown or independent oil companies that you dont know how they blend their products.
Being in Southern California our gas is blended differently then the rest of the US, so I would venture to say that it also depends on the climate and state your in. Thus greatly effecting performance. We have pretty much perfect weather year round here, so worrying about knocks and pings in the winter are moot.
The only difference overall is what is done by the gas co when they create their blend of gas for the consumers.
I remember there was something on the Discovery channel about oil and gas distribution, which basically confirmed that its at the last step at the refinery that differentiates one brand from another as they are all using the same distribution system to refine the oil.
Science, Marketing or Psychological? Pick your blend!
