It was a sales pitch that turned out to be too good to be true: diesel cars that could get upward of 40 miles per gallon, deliver a muscular performance on the road and still comply with U.S. clean-air rules.
The truth was revealed last month, when government regulators announced that Volkswagen had installed software in its cars that switched off part of the emissions system unless the car was being smog tested. Sometime soon, VW will have to recall 482,000 diesel cars sold in the United States since 2009, and as many as 11 million worldwide.
For VW customers, the big question now is whether their diesel cars will still be as fuel efficient and zippy to drive after they’ve been altered to stop them from spewing nitrogen oxides, a key component of smog, at up to 40 times the allowed standard.
Len Brewster, a Detroit-based auto industry analyst, says VW customers have good reason to be concerned. “Based on what I’ve been hearing from engineers, fixing the emissions system will result in decreased fuel economy and performance,” he said. “That will also hurt resale value.”
Because diesel fuel has more energy than standard gasoline, diesel-fueled vehicles have more power and can go about 20 percent farther per gallon than gas-powered cars. The trade-off, however, is that diesels historically emitted toxic air contaminants and relatively large amounts of fine particles harmful to humans.
Diesel cars started to disappear from the California market when strict air-quality standards were phased in starting in 2004. In 2007, no light-duty diesels were certified in California, according to the California Air Resources Board. Diesels started returning to the market in 2009, touting technology to meet state requirements.
Among automakers producing diesels that meet ARB standards since then, Volkswagen rang up high marks. The German automaker dominates a U.S. Department of Energy listing of the most fuel efficient diesels. Some ratings are eye-popping: A 2015 Volkswagen Passat sedan, one of those on the federal list of emissions-evading VWs, is rated at 30 miles per gallon in the city and 42 mpg on the highway. Theoretically, that car, an automatic with a four-cylinder turbodiesel engine, could travel 777 highway miles on one fill-up of its 18.5-gallon tank.
Volkswagen said it solved the air-quality problem with a system that periodically burns off soot and other pollutants that have been trapped in a filter. That mechanism uses fuel that would otherwise be propelling the car. Regulators have not said whether that was the system that was turned off during real-world driving.
So, is there a way to make a diesel-powered car that both meets air-quality standards and delivers solid performance? Allen Schaeffer, executive director of the Diesel Technology Forum, an industry nonprofit in Maryland, noted that other manufacturers, including BMW and Mercedes-Benz, sell diesel cars in the United States as well. Performance reviews vary among models, but some diesels, like the 2015 BMW 328d sedan, at 32 mpg in the city and 45 mpg on the highway, topped VW’s offerings. Still, VW diesel cars hold 13 of the top 17 rankings for combined city-highway fuel mileage on the federal list.
Stanley Young, spokesman for ARB, said that the efforts of BMW and other auto manufacturers meeting diesel-emissions standards show that “the technology exists and can be put to good use.”
Schaeffer argues that the high gas mileage promised by diesel cars makes them a key part of the solution for California, which is working under legislation that requires significant reductions in the carbon emissions linked to global climate change.
“All of that demands fuel-efficient technologies, and diesel is going to be part of that, and has to be part of that,” he said.
VW has not said when it will recall cars in the United States, or what it will do to them when it does. The company is already facing a spate of class-action suits. Some customers have taken to the Internet, angrily demanding their money back.
But some customers would like to find a way to keep their cars. Desmond Wright, a former state worker from Sacramento, falls into this camp.
“The thing is, I’ve been happy with the car,” Wright said of his 2012 Jetta SportWagen, which he bought as a retirement gift to himself. He said it gets 50 miles to the gallon on the highway.
“I have intentions to keep the car,” Wright said. “But a lot will depend on how much change there is in (fuel mileage) and performance. If it was say, 10 percent, I’d still be getting something like 45 miles per gallon (on the highway), and that would be substantially more than a lot of others are getting.”
That may not be enough for car buyers like Virginia White, a former Volkswagen owner. The Sacramento resident bought a Toyota hybrid in June, but maintained an interest in VW diesel offerings before Volkswagen admitted that it cheated on emissions tests.
“I’m now totally disgusted with Volkswagen,” White said. “I would never go back.”
White, 38, said she was particularly upset that Volkswagen marketed its diesel vehicles “on this incredible breakthrough. It was all clean and good, not like those old smelly diesels from years ago (that) were so noisy and made a cloud of (emissions) when they drove down the street.”