Refueling with premium gas can add a significant amount to your annual bill compared to buying regular gas, but in New York, buyers might be receiving lower grade fuel regardless of what they pick. A recent study published by The City found that the vast majority of gas stations in New York had failed inspections by city officials at least once since 2023. Across those inspection failures, incorrect octane levels in gas samples was cited as the main offence.

Ensuring that you fuel your car with the correct octane gas is important, since using a lower grade can result in knocking or engine damage. However, since there is no way for drivers to independently verify the octane of the gas they’re buying every time they fill up, they have little choice but to trust the gas station to deliver the correct product.

City inspection officials carry out periodic inspections to check that gas stations are compliant, but the study suggests that the scale of the problem is making it difficult for inspectors to keep up. According to inspection records, 702 gas stations in the city were caught selling gas with mislabeled or incorrect octane during the study period. The city checked 729 gas stations during that period, so only 27 stations consistently met the required standard.

While New York has a serious problem with gas stations misselling lower octane gas as premium, drivers in other parts of the country are not necessarily as likely to face the same risks. In an interview with 8 News Now, Las Vegas gas station inspector Kipp Blauer said that he only rarely finds premium gas pumps that deliver lower octane fuel, because pipelines that supply the city are only able to deliver a certain grade of fuel at a certain time.

In other states, contamination of premium gas might be more of a risk to drivers than ending up with mislabelled or lower octane gas. In 2025, reports emerged of drivers in Connecticut and Tennessee suffering significant engine issues after filling their cars up with fuel. One affected driver in Connecticut was reportedly quoted $17,000 to fix their BMW after a gas station allegedly put diesel fuel in its premium gas storage tank. In Tennessee, a Memphis gas station reportedly sold premium gas that had been contaminated with water, leaving one car owner with a bill of over $1,000 to fix the damage.

Even if you do pay for premium gas and receive the correct product, it might not make a difference to the performance of your car. It’s a common myth that many drivers believe, but research by the AAA found that premium gas doesn’t automatically come with performance benefits, and it might not be worth the cost for many drivers.

The study’s tests found that some cars that recommended — but did not require — drivers to use premium gas showed slightly increased fuel efficiency and performance with higher octane fuel. However, these benefits were only noticeable during high-stress driving such as towing or hard acceleration. Under everyday driving conditions on the highway or in the city, no noticeable benefits were observed.

If you regularly buy premium fuel, it’s important to check whether your car recommends or requires it. If the car only recommends using premium gas, then the AAA’s research suggests that the added cost might not be worthwhile. However, using lower grade fuel in a car that requires premium gas can reduce its engine’s lifespan, and so it’s important to be careful when choosing the right octane for your car. If your car requires premium fuel, manufacturers often attach a sticker declaring that requirement on the inside of the gas cap, but if you’re unsure, it’s best to check your owner’s manual.