I was at a dealer picking up parts for my bike. While I was shopping one of the guys was on the phone giving advice to someone. Maybe I missed something because I couldn't hear the other side but I just about crapped my pants. He told who ever was on the other side of the phone that "Its better if you run low grade fuel when at altitude because of the low oxygen content in the fuel....." huh? I get that you CAN use a lower grade fuel at higher altitude because of the lower effective compression ratio at altitude but lower oxygen content makes for better fuel and a better running engine at altitude? By my logic I would think that if higher grade fuel really did contain more o2 then you would want to run the higher grade fuel. Am I being stupid?