Mississauga is the strongest fuel market in the GTA west of Toronto, and it usually shows at the pump. Two Costco gas bars — Heartland on Rodeo Drive and the Dundas Street East location near Dixie — set an aggressive floor, and the dense competition along Hurontario, Dundas, Derry Road and the airport corridor keeps the majors within a few cents of it. Drivers here routinely pay less than they would across the Etobicoke border.
Two practical notes. First, avoid filling right around Pearson: the airport-adjacent stations on Dixon and Airport Road price for rental returns and travellers, not for locals. Second, the Heartland retail node is a reliably cheap pocket even without a Costco card, because everything around the warehouse prices against it. The list below ranks every Mississauga station we track by current price, refreshed hourly.