Hypermilers get 81 mpg in cross-country trek

With little more than 100 gallons of diesel fuel, two guys in a 2015 Volkswagen Golf just finished driving a circuitous route that took them through the 48 contiguous states.

That was a journey of 8,233.5 miles in which they averaged 81.17 miles a gallon over 16 days. Volkswagen, which announced the finish of the trip Tuesday, says it's good for a Guinness record.

But these were no ordinary guys. One was Wayne Gerdes, one of the country's best known "hypermilers." He is an expert in squeezing the last few inches out of every drop of gas. His wingman was Bob Winger, an electronic engineer.

Gerdes, VW says, has set mileage records in 100 vehicles, often employing smart mileage tactics that the average driver would either not know about, or be unwilling to try, to achieve great fuel economy.

The trip was meant to showcase the mileage that can be had in VW's clean diesels.

"Volkswagen's TDI Clean Diesel engines are just amazing," Gerdes says in a statement. "I don't think people realize the potential mileage you can get from them. In our experience, it is possible to get truly impressive mileage results by using just a few simple fuel-saving techniques."