In Canada the gas price is by area I assume, every station in my whole city is within a few cents. Some lower volume or more out of city center stations may cost a tiny bit more. As someone who works in oil and gas, the brands of gas are may be the same base petroleum. For example our local chevron fuel isn't from a chevron refinery, it's actually from a shell or Suncor refinery and may stations are like this. Once the fuel supplier purchases a base gasoline the chevron (as example) mix their additives in. The fuel may be slightly different so its possible one engine may favor a chevron additive vs a shell additive. I tried a few tanks of 87 in mine and my uncle has only ran 87 in his 6.2, a coworker also has only used 87. I didn't notice any difference to normal driving at all, I was surprised how much the engine ticks while at idle (chevron 94) the tick didn't change at all with 87. Everyone pokes gun at the hemi tick and my 5.7 hemi with 100k is smoother than my 3500km 6.2 GM Sent from my SM-N975W using Tapatalk