Costco Gas Prices Today: Why You're Paying More Than You Think

I pulled into the Costco gas station on El Camino Real at 7:23 AM on a Tuesday. The line already stretched 12 cars deep. The price board read $3.89 for regular—45 cents cheaper than the Chevron down the street.

Here is something most people get wrong: they think Costco gas is always the best deal. That's not true today, and it hasn't been for months.

The $60 annual membership fee works out to $0.16 per gallon if you buy 375 gallons a year—about what a typical two-car household uses. That math assumes you only buy gas at Costco, which nobody actually does.

Most Costco members I know fill up there once every three weeks. The rest of their gas comes from other stations. That dilutes the savings to nearly nothing.

Let me give you the real numbers. In Sacramento last week, my friend paid $3.87 at Costco. The ARCO across the street was $3.91. He waited 11 minutes in line. His time is worth roughly $25 an hour.

That 11-minute wait cost him $4.58 in lost time. His actual "savings" from choosing Costco? Negative four dollars and 22 cents.

This is the hidden economics nobody talks about. Costco gas is cheap per gallon but expensive in every other currency you spend.

The membership model forces you to prepay for access. Then they bank on your time being worthless. They're usually right—most people vastly overestimate their hourly value.

But here's the twist: Costco's gas isn't even that good. They sell Top Tier detergent fuel, sure. So does Shell, Chevron, and Exxon. The difference in engine cleanliness between Top Tier and non-Top Tier is real but marginal—maybe $50 in engine repairs over 100,000 miles.

What you really need to watch is the price gap between Costco and nearby stations. Today in Los Angeles, that gap averages 38 cents. In Phoenix, it's just 22 cents. In Seattle? 31 cents.

When the gap is above 30 cents, the math starts making sense even with the wait. Below 25 cents, you're losing money on time alone. Check GasBuddy before you go.

The real reason Costco keeps prices low isn't to save you money. It's to get you inside the warehouse. Once you're there, you'll buy a $5 rotisserie chicken you didn't plan on and a 48-pack of toilet paper.

Gas is the loss leader, not the product. You are the product.

What matters most right now is the trend. Gas prices have dropped 14 cents nationally since last month. Costco's discount relative to market has shrunk from 40 cents to 29 cents in that same period.

If that trend continues, Costco gas becomes a bad bet within three months. The line will still be there, but the savings won't be.

Watch the spread, not the price. If your local Costco is only 20 cents cheaper, skip the line. Go to the Arco or the mom-and-pop station with the beat-up sign. Your time is worth more than you think.

I'm still filling up at Costco today—the gap here is 45 cents. But I'm watching that number like a hawk. The moment it drops below 30, I'm done waiting.