Premium gasoline is typically higher-octane than regular gasoline and in most U.S. markets is 91–93 octane (AKI), not 87. Exact numbers vary by country, region, and brand. Always check your vehicle's manual or the fuel door sticker to confirm the recommended grade.
Octane ratings measure a fuel's resistance to knocking under compression. The labels regular, mid-grade and premium correspond to different octane ranges. In practice, premium is the highest grade offered at a given station and is designed for engines that require higher resistance to pre-ignition. The key here is to match the grade to what your car requires.
What octane ratings mean
Octane ratings tell you how much compression the engine can handle before the fuel detonates. Higher compression engines, turbocharged setups, or engines with aggressive timing benefit from higher octane, while most everyday engines run fine on regular gas. The numbers below reflect typical U.S. labeling, but other regions use different scales.
- 87 AKI: Regular unleaded; the baseline grade at most U.S. stations and many international markets.
- 89 AKI: Mid-grade in some markets; not universally available.
- 91–93 AKI: Premium unleaded; widely available and labeled as Premium at many stations; 93 AKI is common, though exact availability varies.
Note: AKI is the U.S. standard; elsewhere, ratings may use RON or another scale. Always follow your owner’s manual or the pump label for the recommended grade.
Regional differences in premium labeling
Understanding local labeling helps you read the fuel labels at the pump and choose the right grade for your car.
- United States: Regular is typically 87 AKI; premium commonly 91–93 AKI; some stations offer 92 or 93; mid-grade 89 is available in some areas.
- Canada: Regular is typically 87–89; premium commonly 91–93 AKI, with some brands offering 94.
- Europe and other regions: Fuel is often labeled by RON; premium typically ranges from about 95 to 98 RON, which roughly aligns with higher AKI in the U.S., depending on testing standards.
Because octane scales differ by country, the exact numbers on signs can vary. The best practice is to use the grade recommended by your vehicle's manufacturer.
Does your car actually need premium?
Most cars designed for regular unleaded will run on 87 octane without issue. Premium is recommended for engines with high compression, turbocharging, or advanced timing to prevent knocking and to preserve performance. If your car’s manual says premium is required, use premium; if it says premium is recommended, you can decide based on performance and cost.
- Check the owner’s manual or the fuel-filler-door label for the exact requirement.
- If you hear knocking or pinging on regular gas, consider using premium or have the engine checked.
- In many modern engines, using premium when not required yields little to no improvement in performance or efficiency.
In short, most drivers can use regular 87 octane unless the manufacturer specifies premium for your vehicle.
How to verify the right grade for your car
To avoid misfueling and potential engine issues, follow the steps below and refer to the manual for definitive guidance.
- Consult the owner's manual for the recommended octane rating and any notes about premium requirements.
- Check the fuel-filler-door sticker or the dashboard label for the recommended grade.
- If in doubt, ask a mechanic or the dealership, especially for performance or turbocharged models.
Using the recommended octane ensures optimal performance and longevity without overspending on unnecessary fuel.
Summary
Premium gasoline is not universally fixed at 91 or 87; in the United States, premium is typically 91–93 AKI, while 87 AKI is regular and 89 AKI is mid-grade in some markets. Europe and other regions use different scales like RON, with premium often labeled around 95–98 RON. Always follow the vehicle manufacturer's recommendation and read the pump label to choose the appropriate grade for your car.