Originally Posted by 1965tripleblack
Top Tier gasolines all have proprietary detergent formulas. Is it possible/probable that a degradation of effectiveness happens if mixing between different brands occurs?
While I wouldn't recommend anyone to arbitrarily mix fuels, unless you are tuned to a razor's edge to just one type fuel, the likelihood that you'd notice a difference if mixing fuels would be slight. The biggest thing that will degrade fuel is age and exposure to the elements- especially water.