Interesting article on fuel economy and buyer habits in Canada from the World Economic Forum:
Canada has the worst fuel economy in the world. Here's why
TL,DR:
Far and away the biggest reason for Canada’s fuel inefficient vehicles comes down to cost. Simply put, the cost to purchase and operate a gas guzzler in Canada (or the U.S.) is far less than the rest of the world.
This cost difference comes in two forms: upfront charges for vehicle registration and gas prices.