What Do the Yellow Buttons and Numbers on Gas Pumps Mean?
- RoadTour.Net Team
- 3 hours ago
- 4 min read
While filming new episodes for Road Tour Television, we came across a wide variety of fuel options at gas stations across our travels. If you've fueled up at a gas station anywhere in the United States, you've probably noticed the bright yellow buttons on the pump labeled with numbers such as 87, 89, or 93 like we did. We also saw 85 as well. Something we've seen since we started driving. But what does it mean? Millions of drivers press one of these buttons every day, but many people—especially first-time drivers, international visitors, or those renting a vehicle—aren't entirely sure what those numbers actually represent. The answer is simple: those yellow buttons allow you to choose the octane rating of the gasoline you want to purchase. But first we want to say ALWAYS put the manufacturer recommended gas in your car. If you are unsure how to get this information you can look it up in your owner's manual or talk to a dealership.
What Is Octane?
Octane is a measurement of a gasoline's ability to resist engine knocking, also known as pre-ignition or detonation. Knocking occurs when the fuel-air mixture ignites too early inside the engine's cylinders, creating unwanted pressure that can reduce performance and potentially cause damage over time.
Higher-octane gasoline is designed to better withstand this premature combustion. However, a higher octane rating does not mean the fuel contains more energy or automatically improves fuel economy.
Common Fuel Grades
Most gas stations in America offer three primary gasoline options.
87 Octane (Regular)
Regular gasoline is the most commonly purchased fuel in the United States. It is recommended for the vast majority of passenger cars, SUVs, minivans, and pickup trucks on the road today. If your owner's manual recommends regular gasoline, this is the button you should choose.
89 Octane (Mid-Grade)
Mid-grade gasoline offers slightly greater resistance to engine knock than regular fuel. Some manufacturers recommend it for specific engines, while many drivers simply skip this option altogether unless their vehicle specifically calls for it.
91, 92, or 93 Octane (Premium)
Premium gasoline is intended for vehicles with high-performance or turbocharged engines that require a higher octane rating. Depending on where you live, the premium option may be labeled as 91, 92, or 93 octane.
A little less common...
E85
Only Flex Fuel Vehicles (FFVs) are designed to run on E85. These vehicles have fuel system components and engine software that can automatically adjust to different gasoline and ethanol blends. E85 is often sold at a lower price than regular gasoline. However, because it provides fewer miles per gallon, the lower price doesn't always result in lower overall fuel costs. Drivers should consider both the price per gallon and the expected fuel economy when comparing costs. As a reminder, most gasoline-powered vehicles are not designed to use E85. Filling a non-flex-fuel vehicle with E85 can cause poor engine performance, hard starting, damage to fuel system components, and expensive repairs.
Does Premium Gasoline Make Every Car Better?
One of the biggest misconceptions is that premium gasoline is automatically better for every vehicle.
In reality, if your vehicle is designed to run on regular 87-octane fuel, using premium gasoline usually won't increase horsepower, improve fuel economy, or extend engine life enough to justify the additional cost. Modern engines are engineered around specific fuel requirements, and following the manufacturer's recommendation is generally the best choice. On the other hand, if your owner's manual specifies premium gasoline, consistently using a lower octane fuel can reduce engine performance and, in some cases, lead to increased engine knock.
Why Are the Buttons Yellow?
The yellow color helps make the fuel selection buttons easy to identify. The bright labels stand out against the pump and clearly display the available octane grades, making it easier for drivers to select the correct fuel before fueling begins. Although pump designs vary by manufacturer and gas station brand, the yellow octane buttons have become a familiar sight across much of the United States.
What About Diesel?
If your vehicle uses diesel fuel, do not press one of the gasoline octane buttons. Diesel pumps are typically located separately or have clearly marked green or black handles, depending on the station. Diesel fuel is completely different from gasoline, and accidentally filling the wrong fuel can result in expensive repairs.
Can Octane Ratings Vary?
Yes. Depending on the region, altitude, and fuel supplier, you may see different combinations of octane ratings.
For example:
87 • 89 • 91
87 • 89 • 93
85 • 87 • 91 (common in some higher-elevation states)
These differences are normal and reflect regional fuel standards.
Those yellow buttons on the gas pump serve an important purpose—they let you choose the gasoline grade that matches your vehicle's engine requirements. While premium fuel has its place, higher octane isn't automatically better. The best practice is to follow the recommendation in your vehicle's owner's manual and choose the fuel grade your engine was designed to use. The next time you stop at a gas station, you'll know exactly what those yellow numbers mean—and why selecting the correct one matters.
Comments