As the weather gets warmer, a gallon of gasoline is actually less potent than it would be if it were cooled. Almost all materials expand as they get warmer. This is a basic law of physics: as matter gets warmer, the molecules that compose the matter begin to move faster, causing the matter to expand. However, while volume (the amount of space the gasoline occupies) may change, the actual amount of gas stays the same.
So, if you buy gas during warm weather, it is entirely possible that the gas has expanded in its storage tank, but the actual amount of gas present has not changed. What this means is that a gallon of warm gasoline will not take your car as far as a gallon of cold gasoline. Because gas is sold by units of volume, not mass, this means that during periods of warm weather, a consumer has to spend more money for the same amount of gasoline.
Some have estimated that this phenomenon causes Americans to buy and additional 513 million gallons of gasoline per year. This sounds like a lot, and it is. However, Americans buy about 146 billion gallons of gas per year. So, about 0.35% of America’s total gas purchases can be attributed to this change in volume.
These facts have given rise to some recent lawsuits, especially in states where weather is typically warm, such as Florida. Because the amount of money lost by an individual consumer because of this phenomenon is extremely small (on average, about 0.35% of the total amount spent on gas), an individual lawsuit is not likely to be worth the cost.
If a consumer hopes to receive a meaningful settlement, he or she should consult a defective products attorney about filing or joining a class-action lawsuit on the matter.