Pay for Canadian gas in Canadian dollars. Always.

The pumps will happily take your U.S. dollars, but the exchange rate they offer is terrible — worse than the airport, worse than your bank. If you’re paying with a card, use one that waives foreign transaction fees and choose “charge in CAD” at the terminal (dynamic currency conversion is a trap — always decline it). Cash? Hit an ATM on the Canadian side for CAD before you fill up. The savings aren’t life-changing, but why pay extra for the privilege of buying the same gas?