Two problems. One, as pointed out, you're going total km, not l/100 km. Absolutely no way to tell if you're using the exact same amount per tank, and extremely unlikely that you are. Two, is that as far as I know, CO-OP, much like Safeway, Can Tire, etc. Don't always get their supplies from the same place. I've seen various trucks refuelling the Safeway tanks in Cochrane.
That being said, I too have always found better anecdotal results with Shell, and use the 91 exclusively from them on my vehicles that require it, due to the lack of ethanol.
|