They put it on clearance some months ago. Not sure exactly why, but they're not stocking it anymore.
I found this on the Marvel web forum...
"Unfortunately, Canadian Tire didn't keep Marvel Mystery Oil in their product offering this year.
We sell most of our products through distributors so it is difficult to pinpoint the re-sellers in Canada who may be selling Marvel. My recommendation is to try a local hardware store such as ACE. And make sure to let your local Canadian Tire that you would like to see Marvel back on their shelves.
Thanks for supporting Marvel!
Marc Okicich
Director of Marketing
Marvel Oil Company"