A turbocharged direct injection-powered Volkswagen Passat has conquered a drive across all but two (Alaska and Hawaii) US states in one piece.
It covered 13,071km with record low fuel consumption and within 16 days.
The record drive was witnessed by officials of the Guinness World Record Organisation.
Drivers Wayne Gerdes and Bob Winger achieved fuel consumption of only 3.02-litres per 100km, which translates as a range of 125.5km per 3.78-litres.
"We felt we had a good chance of beating the existing record with a series production Passat TDI," Gerdes says, "but to smash it by averaging 77.99 miles per gallon is really impressive and a testament to the potential of Volkswagen's TDI vehicles.
'It shows how much the fuel consumption depends on the driver."
The previous world record was set at 67.9 mpg (3.46 litres per 100km).
The record-breaking Passat, built at Volkswagen's Tennessee plant, offers an official highway fuel economy of 43 miles (69.2km) per gallon (Energy Policy Act) equipped with the six-speed manual transmission (5.5-litres per 100km).