How Much Regular Gas Are You Getting with Your Premium Fill-up?

Premium gas costs more, but are you really getting what you pay for? It might be time to reconsider whether you ride a motorcycle and fill it up with high-octane fuel because you expect better performance. New research shows that if the pump was just used for regular gas, you might have some of it in your tank, even if you select premium.

What Happens at the Pump?

A recent RevZilla investigation revealed something surprising: most gas stations use a single hose for all fuel grades. That means when a customer pumps regular gas before you pump it, leftover gas remains in the line. If you select premium, you will get a mix, not pure high-octane fuel.

How Much Regular Gas Are You Getting?

Fuel dispensers typically hold about a third of a gallon in the hose. When you fill a motorcycle tank with only two to four gallons, that leftover regular gas can dilute your premium fuel by eight to sixteen percent. While this likely won’t damage your engine, it cancels out the benefits of paying for premium. If you’re set on getting full-strength premium, consider letting a few seconds of fuel run into a gas can first to clear the hose. Otherwise, be aware that your “premium” might not be pure, and you could be wasting money without realizing it.

Is Premium Gas Worth It for Motorcycles?

Many riders assume premium gas boosts horsepower or protects their engine, but that’s not always true. Only motorcycles designed explicitly for high-octane fuel actually need it. Most bikes run just fine on regular unleaded without any harm. Check your owner’s manual—if it says “premium recommended,” regular is usually safe. But if it says “premium required,” don’t risk it. Otherwise, you’re just paying more for no real benefit. Understanding your bike’s needs can save you money without sacrificing performance or engine health.

What the Octane Rating Really Means

Octane measures a fuel’s resistance to engine knock, not its quality. A higher number doesn’t mean more power. The Federal Trade Commission confirms premium gas won’t make your engine cleaner or run better unless your vehicle’s manufacturer specifically requires it. For most engines, regular gas works just fine.

What Riders Need to Know About Mileage

Motorcyclists often associate premium gas with better fuel economy. But real-world results don’t always match that assumption.

Average Gas Mileage of a Motorcycle

Most street motorcycles get between 35 and 60 miles per gallon. Fuel efficiency depends on engine size, riding habits, wind, and tire pressure. The U.S. Department of Energy notes that premium gas rarely improves MPG in bikes that are not built for it, meaning you probably won’t see better mileage just by upgrading your fuel.

Best Gas Mileage Motorcycles

Smaller bikes get the best gas mileage. The Honda Grom, Kawasaki Z125, and Yamaha MT-03 can hit over 70 MPG if conditions are right. They’re built more for saving fuel than going fast, and most of them run just fine on regular gas. If you’re trying to save money, they are solid options.

When Paying More Doesn’t Mean Getting More

Paying extra for premium gas might feel like you’re doing your motorcycle a favor, but that’s not always true. If your bike doesn’t require high-octane fuel, and especially if you’re filling up from a shared hose, you could get a blend of regular and premium without realizing it. That extra cost adds up fast, often without any real improvement in performance or mileage.

Law Tigers knows that fueling smart matters. Check your owner’s manual, and when possible, use pumps with separate hoses to avoid dilution. Your engine—and your wallet—might thank you.