The purpose of this ruling is supposedly to prevent people from pumping gas with ethanol into small engines, motorcycles, scooters, etc. because the ethanol can harm those engines.
The reasoning is that these machines have tanks with a capacity of less than 4 gallons, so this law will force people to fuel them at non-ethanol gas pumps which are not subject to the 4 gallon minimum requirement.
But, like other bright government ideas thought up by bureaucrats sitting in cubicle farms, they never seem to see the unintended consequences.
Example: The bureaucrats seem to think that gas stations offer both types of gasoline in pumps side by side. But in my area there are no longer any regular gas stations selling pure gas without ethanol. Supposedly the pure gas is available at marinas, airports, etc. but what help is that to the average driver or homeowner? Or the guy who ran out of gas and only has a two gallon gas can?