Should I use 87 or 91 gas?
The short answer is that it depends on the specific requirements of your vehicle. In general, using the recommended octane rating for your car is the best choice. Higher octane fuels like 91 are typically only necessary for high-performance or luxury vehicles, while regular 87 octane gas is suitable for most standard passenger cars.
Understanding Octane Ratings
Octane ratings measure a fuel's resistance to premature ignition, also known as "knocking" or "pinging." Higher octane fuels can withstand greater compression before igniting, making them better suited for engines that operate at higher compression ratios. Vehicles with high-performance engines often require premium 91 or 93 octane gas to prevent knocking and engine damage.
However, for most regular passenger vehicles, the recommended octane is typically 87. Using a higher octane fuel than what's specified by the manufacturer won't provide any additional benefits and will simply cost you more at the pump.
Choosing the Right Octane for Your Vehicle
To determine the right octane for your car, check the owner's manual or look for a sticker inside the driver's side door jamb. This will specify the minimum octane rating recommended by the manufacturer. Using a fuel with a lower octane than recommended can lead to engine knocking, which can cause damage over time.
If your vehicle is designed for regular 87 octane gas, there's no need to use premium 91 or higher. The higher octane won't provide any performance or fuel economy benefits, and you'll just end up paying more per gallon.
Exceptions and Considerations
- High-performance vehicles: Cars with high-compression engines, such as sports cars or luxury models, often require premium 91 or 93 octane fuel to prevent knocking and engine damage.
- Older vehicles: Older cars with lower compression engines may benefit from using a higher octane fuel to prevent knocking, even if the manufacturer recommends regular 87.
- Fuel quality: In some regions, the quality of 87 octane gas may be lower, making it more prone to knocking. In these cases, using a higher octane fuel may be advisable.
Ultimately, the best fuel for your vehicle is the one recommended by the manufacturer. Following their guidelines will ensure optimal performance and fuel efficiency while avoiding potential engine damage.
What happens if I use 91 instead of 87?
Engine computers can usually adjust their timing to account for the increased octane levels, so if you put premium gas in a regular car, you probably won't notice anything. However, some engines are not designed to burn higher-octane fuel, and you may see a reduction in performance and fuel economy.
What burns faster, 87 or 91 octane?
Fuel with an 87 octane rating burns more quickly while higher-octane fuels burn more slowly. In engines designed for standard unleaded fuel, efficiency and performance is optimized for 87 octane and could actually perform worse with higher-octane fuel since the burn rate is slower.
Does 91 octane make your car run better?
The Federal Trade Commission recommends using regular gasoline for most standard cars and notes that: "In most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage, or run cleaner."
What if I accidentally put 87 instead of 91 on Reddit?
You'll be fine. If it's just a regular car and not tuned specifically for a specific octane. Knock sensors will do their job and pull back ignition timing. Just don't do it often.
