My experience is that Amoco, any grade, is hands down the detergent king of gasolines. I know within two tankfuls if my wife has filled up with even the premium grades of local convenience store brands: low idle, stalling, obvious injector deposits. One tankful of Amoco cleans everything up, at a cost of about seven cents per US gallon. This is much less expensive than running Techron through the tank every month.