We're assuming the company cares wheather the containers are all filled with exactly 1 gallon. This material is not that rare or expensive. I would geuss the margin for error is between .5 and 1%. The indutry has no critical regulation such as mil-spec or FDA to warrant the manufacturer to place such precise controls on the process which increases cost. Byrons costs more because they charge more and they make more profit. It could be better than the stuff I buy, but not twice as good. Byrons cost is double the brand I fly, Does my fuel have 14.99745% nitro or 15.00328%? I don't care, neither does my wallet.