Cosnumer Reports says that top tier gasoline is better and gives you better gas mileage so if you drive a lot and/or have a car you want to keep around, it might be better to use a top tier brand …

• All retail locations within the licensed country must meet the high standards of the TOP TIER™ program.
• All gasoline grades must be treated with an approved TOP TIER™ Detergent Gasoline additive at the correct concentration.
• The TOP TIER™ logo must be prominently displayed. 
• TOP TIER™ licensed retailers agree to not use organometallic additives (such as MMT or Ferrocine).
• Find more information here.
• Download the AAA Station Locator to find a station near you.

Check out the FULL LIST HERE.