Two of the world’s most fuel efficient drivers, John and Helen Taylor, are a third of the way through their attempt to break the current world record for lowest fuel consumption across the 48 contiguous United States. Today they will be driving into their ninth day, passing through the northern states of the Great Plains, including South Dakota, North Dakota and Montana. To help them along the way, they are driving the all-new, 50-state-compliant clean diesel Volkswagen Jetta TDI, fueled by Shell’s best diesel fuel.