Using 91-octane premium fuel instead of 87-octane regular fuel will only increase your engine's power if your car's manufacturer specifically designed the engine to require it.
Higher octane fuel resists knocking or 'pinging' under compression, which is a premature ignition of the fuel-air mixture. Engines designed for higher octane can take advantage of this resistance to operate at higher compression ratios or with more advanced timing, which can lead to increased horsepower and efficiency. However, if your vehicle's owner's manual specifies regular 87-octane fuel, using premium 91-octane will likely offer no discernible performance benefit and is generally not recommended. Always consult your vehicle's manual for the correct fuel grade.
Fuel octane requirements are determined by the vehicle manufacturer and using a higher octane than recommended typically provides no benefit.
Is there a significant price difference between regular and premium gas?
Yes, there is typically a noticeable price difference between regular and premium gasoline at the pump. Premium gasoline (91 or 93 octane) generally costs more per gallon than regular gasoline (87 octane). This price difference reflects the more complex refining processes and potentially higher costs associated with producing fuel with a higher octane rating. The exact price gap can vary by region, gas station, and market conditions, but it's common to see a difference of $0.20 to $0.50 per gallon or more. This cost difference is a key consideration when deciding if premium fuel is necessary for your vehicle.