‘Can Anyone Explain?:’ Man Pumps Gas at Shell Station. Then He Takes a Closer Look at Where His Fuel Is Coming From

When a man spotted just two pipes running from the ground into a three-grade fuel pump, he asked a question that earned him plenty of snark online. But here’s the thing: He wasn’t wrong to wonder. If you’ve ever chosen mid-grade gas, you’ve unknowingly been part of a clever little chemistry experiment.

In a clip that’s been viewed more than 3 million times, TikToker Jesse Miller (@jess_m603) looks at the exposed piping on the gas pump he’s using and wonders aloud why only two pipes are feeding into the pump from the underground storage tanks.
He asks, “Does anyone want to explain to me why there’s two pipes that go in, but there’s three (octane) options?”

What Miller stumbled upon is actually how most gas stations across the U.S. work. Despite offering three fuel grades (typically 87, 89, and 91 or 93 octane), many stations only store two types of gasoline underground: regular (87 octane) and premium (91 or 93 octane).

The midgrade option isn’t stored separately; instead, it is created at the pump by blending the other two. This is a standard, regulated practice in the industry, not some shady corner-cutting maneuver. The pump blends the two fuels in real-time to create a consistent mid-grade option, all under the control of precision hardware and software.

How Blended Midgrade Fuel Works

Midgrade blending typically occurs either in the pump’s metering chamber or in the fuel line leading to the nozzle. The proportions are managed by the dispenser’s onboard software, which adjusts the mix according to the octane rating selected by the customer.

For mid-grade, that might mean dispensing 50% regular fuel and 50% premium, although the exact ratio can vary depending on the specific grades used.

The process is highly regulated. Blended fuel must meet strict octane accuracy standards enforced by state Weights and Measures programs. Pump calibration must be accurate to within a fraction of an octane point. Local agencies routinely inspect these dispensers to ensure compliance with these standards.

The practice of blending fuel at the dispenser is a carefully engineered solution that reduces costs and simplifies operations at fuel stations. Most stations are designed with just two underground storage tanks.

Ref: ‘Can Anyone Explain?:’ Man Pumps Gas at Shell Station. Then He Takes a Closer Look at Where His Fuel Is Coming From (motor1)