Another day brings another fuel-economy record, this time from Volkswagen in a diesel-powered Golf TDI. With expert hypermiler Wayne Gerdes and energy engineer Bob Winger alternating shifts behind the wheel, the 2015 Volkswagen Golf TDI drove through all 48 contiguous states of the U.S. on less than $300 of diesel, achieving a record-breaking average of 81.17 mpg along the way.

Over the course of 16 days, the Golf traversed 8,233.5 miles and used 101.43 gallons of diesel fuel. While we don't know how slowly the two hypermilers were driving, we can imagine that the average speeds were quite low given the impressive efficiency results. The mileage figures from this trip nearly doubled the standard 2015 Volkswagen Golf TDI's EPA highway number of 45 mpg with the six-speed manual transmission.

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The end result was enough to beat the Guinness World Record for "lowest fuel consumption—48 U.S. contiguous states for a non-hybrid car," beating the previous record of 77.99 mpg. The Golf TDI also beat the hybrid vehicle record, which stands at 74.34 mpg.

The Volkswagen team was sponsored by Shell and Goodyear, among others, so it's no surprise that the record attempt relied on Shell ultra-low-sulfur diesel fuel and Goodyear Assurance Fuel Max tires. The Golf was also outfitted with a special wrap touting the car's North American Car of the Year award and Volkswagen of America's 60th Anniversary.

If you'd like to try setting this kind of record yourself, all you need is a 2015 Volkswagen Golf TDI hatchback, which starts at $23,165 with destination. Prepare for some slow going to achieve the same result as these record-setting hypermilers.