I was thinking it was worded "55 gallons or more"  That means 55 gallon oils drums count in your capacity.  May have to try and trade a bunch of 55's for 30's.  1 1000 gallon tank, 4 55 gallon barrels,  and an old 150 gallon heating oil tank for used oil and you are over.

Maybe I'll just drive the articulated tractor past the gas station every morning and fill up.  I bet I get free coffee for that!