A Chattanooga-made, diesel-powered Passat has set a new mileage record on a single tank of diesel fuel as it traveled 1,626 miles, according to Volkswagen.
The trip in the standard, six-speed manual Passat from Houston, Texas, to Sterling, Va., averaged 84.1 miles per gallon, or 4.65 cents per mile, the automaker said.
The former record was 1,526 miles achieved in an older design Passat 1.6 BlueMotion diesel in Europe a couple of years ago, according to VW.
"We were confident we could do it," said Helen Taylor, who set the new mark with her husband, John.
The Australian couple are so-called mileage experts who work with car and tire companies and hold other records.
"We approached VW and said, 'This is what we want to do,'" Helen Taylor said.
They said they carefully planned the route, traveling from Houston to Jacksonville, Fla., and then to Virginia using interstate highways over three days. They tried to keep the car in sixth gear when possible.
Also, they said they drove about 5 miles per hour below the speed limit in the Passat TDI featuring a 2.0-liter four cylinder engine running on ultra-low sulfur diesel fuel.
"We'd sit on 60," John Taylor said. "Reducing speed saved 23 percent in fuel."
They also said they kept the car's tire pressure at the proper mark, drove smoothly and consistently and idled as little as possible. They only used air conditioning on two occasions.
The couple added that they carried 120 pounds of luggage and drove during the daylight hours and didn't travel more than 14 hours a day.
Rainer Michel, Volkswagen of America's president of product strategy, said in a statement that the Passat TDI unites driving dynamics and fuel efficiency.
VW typically reports that the TDI can get about 800 miles on a tank of fuel.
Mark Gillies of VW said that's based on U.S. Environmental Protection Agency calculations.
"It has been our experience with independent journalists that it's higher than that," he said.
Diesel fuel sells for more than gasoline. In Chattanooga on Monday, diesel sold for an average of $3.95 a gallon compared to $3.56 for regular unleaded gasoline, according to AAA's Fuel Gauge Report.
Also, the diesel Passat costs more than a comparative gas-engine model. According to VW, the TDI SE model sells for $25,995 while a gas-burning SE goes for $23,725.
Still, officials said last week that the Chattanooga plant plans to up production of the TDI to meet demand.
Contact Mike Pare at email@example.com or 423-757-6318.