Why You Might Not Actually Need Premium Gas
Consumer Reports tested fuel economy and acceleration with different grades of gasoline
Premium gas sounds like it’s something special. But it translates into paying extra for a higher octane without any performance or fuel-economy benefits for many cars.
That’s what we found after running tests at our 327-acre track.
Some cars require premium gas, but others simply carry a recommendation that owners use it. We wanted to see whether owners can save money by using regular gas for cars that manufacturers merely recommend using premium fuel.
How We Tested
To determine whether using regular gas in a vehicle that comes with a recommendation to use premium gas had any effect on fuel economy or acceleration, we evaluated two models: a 2015 Acura TLX four-cylinder and a 2016 Nissan Maxima V6 (both shown below). Each comes with a recommendation—but not a requirement—to use premium gas. That guidance can be found on the inside of their fuel-filler door and is often explained in greater detail in the owner’s manual.
The powertrain warranty should protect owners as long as they fuel the vehicle according to the instructions in the owner’s manual.
Photo: John Powers Photo: John Powers
We contacted Acura and Nissan, asking why both automakers recommend using premium gas.
An Acura spokesperson referred us to the TLX’s owner’s manual, which states: “Use of lower-octane gasoline can cause occasional metallic knocking noise in the engine and will result in decreased engine performance.”
Such sounds are caused by fuel preignition. Over time, this can damage the engine and affect long-term reliability.
A Nissan spokesperson wrote in an email that “it is possible for the same performance to be realized using nonpremium fuel.” But the spokesperson added that there could be some conditions where performance—which includes fuel economy—might be compromised, such as on extremely hot days. Nissan also said that it recommends the use of premium fuel to guarantee advertised performance.
Money in Your Pocket
According to AAA’s national average gas prices, as of March 26, 2025, the difference between regular and premium gas was about 83 cents. Owners who pay for premium gas when they don’t need it can hurt their budget needlessly.
Below we highlight the potential savings using regular instead of premium fuel, assuming 12,000 miles per year and current gas prices.
Savings Using Regular Over Premium Gas
| Fuel Economy | Savings per Year |
| 30 mpg | $332 |
| 25 mpg | $399 |
| 20 mpg | $498 |
| 15 mpg | $664 |
What's the Downside?
It’s okay to use regular even if the manufacturer recommends using premium gas. But you should check your owner’s manual before making the switch, and remember that some automakers say premium is required.
Wondering about the long-term effects of switching to regular fuel? In short, there’s no harm in using regular fuel in vehicles if premium fuel isn’t required by the automaker.
When premium is merely recommended, and the car runs fine on regular, stick with that. But if, over time, it does start making pinging noises, try upgrading to a premium fuel.
If you’re experiencing pinging using the fuel required by the automaker, whether regular or premium, have the car diagnosed by a professional mechanic.
The use of premium fuel in a vehicle that doesn’t require it won’t cause harm, but it’s probably a waste of money.
In the Acura owner’s manual, the automaker recommends only using “Top Tier detergent gasoline”—which can be of any octane grade, regular or premium—for performance and reliability reasons. (Learn more about Top Tier fuel.)
In addition to these test findings, keep in mind that our car reliability data consistently show that the most dependable cars tend to be those running on regular fuel.
