Three companies, Walmart (and its Sam's Club subsidiary), Valero Energy Corp. and Casey's General Stores have joined the ranks of businesses settling "hot fuel" lawsuits, reports the Kansas City Star.

Hot fuel is the term used for the expansion of fuel in warmer temperatures. Because of this, consumers at the pump get less energy per gallon while paying the same price.

Lawsuits in recent years have charged oil companies and fuel providers with failing to adjust prices for temperature changes (although oil companies argue that in the colder months, consumers get more energy per gallon).

These three newest settlements must still be approved by the court's chief judge, Kathryn Vratil, but if she does approve, they will apply to dozens of hot-fuel lawsuits filed around the U.S.

Two weeks ago, BP Products North America Inc., ConocoPhillips Co. and Shell Oil Products US agreed to settle. The details of those settlements are not yet available, but they will likely stipulate that the companies facilitate the adoption of a hot-fuel fix, the Star reported. This would automatically adjust prices for temperature at fueling stations.

Costco Wholesale Corp. settled 2009, agreeing to change pumps in the hottest regions of the country.

When it first started reporting on the issue, The Kansas City Star estimated that hot fuel costs consumers $2.3 billion a year, now $3.5 billion at current fuel prices.