http://www.toptiergas.com/
Top Tier Detergent Gasoline
TOP TIER Detergent Gasoline is a recently established new standard for gasoline performance. Four of the world's top automakers, BMW, General Motors, Honda, and Toyota recognize that the current EPA minimum detergent requirements do not go far enough to ensure optimal engine performance.
Since the minimum additive performance standards were first established by EPA in 1995, most gasoline marketers have actually reduced the concentration level of detergent additive in their gasoline by up to 50%. As a result, the ability of a vehicle to maintain stringent Tier 2 emission standards have been hampered, leading to engine deposits which can have a big impact on in-use emissions and driver satisfaction.
These automakers have raised the bar. TOP TIER Detergent Gasoline help drivers avoid lower quality gasoline which can leave deposits on critical engine parts, which reduces engine performance. That’s something both drivers and automakers want to avoid.
TOP TIER Detergent Gasoline Retailers
Gasoline retailers must meet the high TOP TIER standards with all grades of gasoline to be approved by the automakers as providing TOP TIER Detergent Gasoline.
In addition, all gasoline outlets carrying the brand of the approved retailer must meet the TOP TIER standards.
Additional gasoline retailers are added to the TOP TIER list as they meet the standards. The retailers known to be on the TOP TIER list are shown below.
TOP TIER Gasoline Retailers:
QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company
Kwik Trip/Kwik Star
The Somerset Refinery, Inc.
Chevron-Canada (B.C. only)
At $4.50 a gallon, you'll never get knock. If you have cats then Turbo Blue 100 unleaded is best. I live in metro motor city where there are three Sunoco stations in a three mile radius of me selling this stuff so good luck finding it elsewhere. 
