If you're tuned for 91 octane, running a higher octane will not harm anything.
However, in this situation running Petro Canada's 94 octane will result in a drop in fuel economy due to the increased ethanol content in the fuel compared to their own 91 octane or Shell's 0% ethanol 91 octane.
I have run 94 octane in a number of my vehicles over the years but have found a drop in fuel economy and bank balance from buying the higher grade fuel over normal 91 octane.
However, in this situation running Petro Canada's 94 octane will result in a drop in fuel economy due to the increased ethanol content in the fuel compared to their own 91 octane or Shell's 0% ethanol 91 octane.
I have run 94 octane in a number of my vehicles over the years but have found a drop in fuel economy and bank balance from buying the higher grade fuel over normal 91 octane.