Oil companies sued over "hot fuel" allegations.

WASHINGTON -- U.S. truck drivers and motorists in seven states filed a class action lawsuit against 17 oil companies and fuel retailers for overcharging at the pump for fuel heated above the industry standard. So-called "hot fuel" provides less energy than a standard 60-degree gallon. Like all liquids at hotter temperatures, fuel expands, reducing the energy content. The hotter the fuel -- whether by radiant heat from the sun or from the refinery process -- the more drivers pay for less energy.