Costco stations and discount banners have a solid reputation: you expect to pay less there than anywhere else. That’s often true, but the real savings depend on details that are easy to overlook — the cost of the membership, time spent in line, the limited number of locations and the opening hours. Here’s how to tell whether, in your situation, the detour is actually worth it.
Why these stations are often cheaper
Discount banners and warehouse stations like Costco run on a volume model: they sell a lot, with a thin margin per litre, and use fuel as a loss leader to bring customers in. As a result, their posted price frequently sits below the average of neighbouring stations. It’s a real advantage — but one that isn’t guaranteed everywhere, or every day.
The special case of Costco
The membership
At Costco, the gas discount isn’t available to everyone: you need a paid membership card. The basic (Gold Star) membership costs an annual fee that has to be factored into the math. If you already shop at Costco for other things, the gas becomes a nearly free bonus. But if you pay for the membership only for fuel, you need to buy enough gas over the year for the per-litre savings to beat the cost of the card.
The break-even math
Estimate your savings per litre compared with a regular station, multiply by the number of litres you buy per year, then compare with the membership fee. If the total savings exceed the fee, a “gas only” membership pays for itself — otherwise it only makes sense combined with your other purchases.
Discount banners (no membership)
Independent and discount banners often offer competitive prices without requiring a membership card. They’re generally easier to get to than the warehouses, but their price advantage is more variable: it can be significant one day and gone the next. The same logic applies: a good posted price only counts if it survives the cost of the detour.
How to decide, concretely
- Compare before you leave. Check the actual price at the Costco or discount station and at the regular stations along your route on the price map.
- Account for the detour. If the savings don’t cover the gas and the time of the trip, a well-placed regular station is the better choice.
- Amortize the membership (Costco). Only count its cost if you buy nothing but gas; otherwise, treat it as already “paid for” by your other purchases.
- Check the hours and how busy it gets. A discount that comes with a long lineup at rush hour may be worth a visit at a quieter time instead.
In the end, Costco and discount banners are excellent options when they’re on your way and the price of the day is genuinely low. But they don’t automatically beat the competition: comparing station by station remains your best tool. To go further, see our 10 ways to save on gas and the Montreal vs Quebec City price comparison.
Frequently asked questions
Is Costco gas always the cheapest?
Often, but not systematically. The Costco price is generally below the local average, but a nearby discount station can match it on some days. Compare the actual price of the moment rather than assuming.
Is a Costco card worth it just for the gas?
Only if you buy enough gas in a year for the per-litre savings to exceed the annual fee. With low mileage, the membership generally doesn’t pay for itself through gas alone. It becomes worthwhile if you already shop there.
Is discount gas lower quality?
No. Gasoline sold in Quebec has to meet the same standards regardless of the banner. A cheaper station isn’t selling lesser fuel; it simply operates on a thinner margin.