Premium gasoline carries the biggest markup spread in Edmonton. The premium-over-regular gap ranges from about 12¢/L at warehouse-club gas bars to 30¢/L or more at full-service stations — which means the station you choose matters more for premium than for any other grade. If your vehicle requires 91 octane, picking the right pump can save $8–12 on a single tank versus the most expensive station on the same day.
Nearly every priced station we track in Edmonton sells a premium grade (typically 91 octane; Shell V-Power runs 91+ and Petro-Canada Ultra 94 tops the octane list at 94 — fitting, since Ultra 94 is refined by Suncor just east of the city). Costco deserves a special mention: its premium is usually priced only ~20¢ above its already-low regular, making it the cheapest 91-octane fuel in the city on most days — the members-only line tends to be worth it for any vehicle that must run premium.
One caution that applies to premium more than other grades: only pay for it if your car requires or measurably benefits from it. If your owner's manual says "premium recommended" (not required), modern engines will run safely on regular with a small performance reduction. If it says "premium required", use the list below to pay as little as possible for it.