I guess the question is whether or not people use differing fuel percentages or plug types with different weather conditions/barometric pressures to give optimum performance. Hotter plugs for better idling is a start.
People spend vast amounts of money on their engines and the tiniest performance enhancing techniques, and spend hours trying to fine tune the little suckers and this just seemed like another area to look at. I don't race, I build and bash for fun. But in the colder and wetter days, I like to look at ways I can improve the overall package. As there are so many different fuels etc out there, I wondered if it was a feature in racing.