The delivery company by that name was, at one point, owned by the Purolator oil filter company. (The shipping company used to be named Trans-Canada Couriers.)

The delivery company by that name was, at one point, owned by the Purolator oil filter company. (The shipping company used to be named Trans-Canada Couriers.) Purolator comes from the phrase "pure oil later," as in long-lasting oil filters for combustion engines.