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.
Can I switch between 87 and 91 octane gas without harming my engine?
For most vehicles, switching between 87 and 91 octane gasoline is generally safe, but it's crucial to follow your car manufacturer's recommendation. If your vehicle is designed to run on 87 octane, using 91 will not cause damage but will likely not provide any performance advantage and will cost more. Conversely, if your car requires 91 octane, using 87 can lead to engine knocking, reduced performance, and potentially long-term engine damage. Always check your owner's manual to determine the correct fuel grade for your specific vehicle.