Just filled up, $1.32 per litre for 91, $1.18 for 87 @ Chevron, so only about 50-55 cents a gallon difference here today. last week was $1.37 per litre. Chevron has 94 here as well but I bet its a pretty slow mover this time of year. Once the car was tuned pretty well it stopped pinging except for just off idle in higher gears and I tried some 89 octane, I had to put 91 in two times after for it to stop pinging. again.