Gasoline grades (octane ratings) measure a fuel’s resistance to knocking or pinging—that unsettling sound when fuel ignites too early in the engine. Here’s the quick rundown:

• Regular (87 octane): The budget-friendly choice for most everyday cars.

• Mid-grade (89 octane): A middle-ground option, often for vehicles that recommend but don’t require higher octane.

• Premium (91-93 octane): The high-end stuff, designed for performance engines, turbos, and luxury cars that demand it.

Not every car does! Here’s the breakdown:

• Domestic (Ford, Chevy, Dodge): Most run fine on regular unless they’re high-performance models (think Mustang GT or Corvette).

• European (BMW, Mercedes, Audi): Many require premium due to high-compression or turbocharged engines. Skimping can hurt performance and fuel economy.

• Imports (Toyota, Honda, Hyundai): Typically regular-grade friendly unless it’s a sporty model (Supra, Type R).

• Using Regular in a Premium-Required Car: Engine knock, reduced power, worse fuel economy, and over time—carbon deposits and potential long-term damage.

• Using Premium in a Regular Car: Congrats, you’re burning money. Your Civic won’t suddenly turn into a race car.

If your owner’s manual says "Premium Recommended," you can use regular, but you might lose some pep. If it says "Premium Required," don’t cheap out—your engine will thank you.

At Ric Henry’s Auto Service in San Angelo, we know engines inside and out. Whether you’re debating fuel grades or dealing with knock-related regrets, our experienced technicians use dealer-grade tools to keep your ride running smooth. Plus, we back all our services with a 3-year/36,000-mile warranty—because we stand by our work.

Using premium in a car that doesn’t need it is like putting ketchup on filet mignon—pointless and mildly offensive. Stick to what your engine actually wants, and if in doubt, ask us!