octane effects power and engine temp?

[jdlmodelt]

Hey guys/gals. I topped off my fuel tank last night, about half empty, with 87 octane with no ethanol. this morning I noticed less power. This evening I noticed even less power and the engine was not as snappy to rev and it was running warmer than usual. Oil looks clean, no condensates, coolant level is topped off and clean. I topped off the tank on my way home tonight, 91 octane, the highest I can get here, the engine ran at normal temp and the engine felt a little stronger but not as strong as I'm used to. Did I just get some bad gas? I was able to squeeze 3.4 gallons of 91 octane while topping off tonight.