Paul,
I get asked this question ALOT. There is some problem with what I have posted and hope nobody would find it, however you have. As long as the fuel contains the same constituents the previous post holds true. The problem is that each company has their own ingrediant. Detergents, flame increasers, anti-foam, emulsifiers, and so-on. That is why some fuels burn better than others in some situations. Without pulling out one of my college papers and re-writing it, it is best to use the minimum octane required, that is if the gasoline is "fresh" and from a known supplier. The canadian gasoline varies ALOT from the US based fuels as well as from station to station. We tested some 150 different fuels. Some were from the same manufacturer but different state. The difference is mind blowing. Each manufacturer has their own distilation curve, that is what depicts what properties the fuels contain. I can tell you that SUNOCO is a HOTTER fuel than MOBILE, only a few BTU's but... Mobile also has more detergent than CITGO. Does it make it a better fuel?? Not really. Some facts: gasoline has a Sg of .72-.76. Contains about 20,000 btu/lb. The list goes on and on.
GLH