⚠ The Fuel Trip Disappears With the Combustion EngineModerate threat

Costco's own risk factors put the exposure in one sentence: "We sell a substantial amount of gasoline, the demand for which could be impacted by concerns and regulation about climate change."¹

The revenue at stake is around 10% of net sales, but revenue understates the problem and margin overstates the relief. Because fuel is sold at close to no margin, losing it would barely dent operating income directly — and might even raise the reported gross margin percentage. The real loss is the trip. A member who fuels an electric car at home has no weekly reason to enter Costco's car park, and the frequency component of comparable sales is the number that renews a membership.

The transition is slow, uneven by market, and partly reversible, so this is a decade-scale drift rather than a cliff. Costco is not passive about it — the same forecourt real estate can host charging, though charging takes twenty minutes rather than four and changes the economics of the queue entirely, in a direction that might actually favour a retailer with a food court.

There is a second-order accounting effect worth understanding. Because fuel is roughly a tenth of net sales at nearly zero margin, its shrinkage would mechanically raise Costco's gross margin percentage and its SG&A percentage at the same time, making the reported ratios look better while the business got worse. Any reader tracking margin alone would misread it completely.

Watch the gasoline volume change Costco reports each quarter, not the sales figure. Falling gallons in mature markets, sustained across several years, is the early signal — and it would show up in frequency before it showed up anywhere else.