When you pump gas from anywhere you really don't know what you are getting these days.
Typically the higher the octane the cooler and slower the burn thus you are actually making less power.
The more ethanol in fuel the cooler yet leaner the burn also making less power. More ethanol or oxygenators in the fuel requires more fuel to make the same power. In carbed motors this means bigger jets and in injected motors, bigger injectors or increased injector duty cycle thru the ECM calibrations.
My guess is maybe you got some 15% ethanol fuel which would certainly account for the sluggish performance of a motor tuned to run on pure gas.
Edited by Muzzlebrake (07/27/17 07:19 AM)
From Genesis: "And God promised men that good and obedient wives would be found in all corners of the earth."
Then He made the earth round...and He laughed and laughed and laughed!