Fuel is chemically less stable than ever before. This is due, in large part, to the use of ethanol as an octane-boosting ingredient. Elaborating, alcohol oxidizes and emulsifies to form non-combustible byproducts.
Over time these can build up in fuel injectors, on the backsides of intake valves and throughout an engine’s combustion chamber. The result [of this] is loss of engine performance, reduced fuel economy, increased emissions, hard starts, etc.,
