How GM Got Caught In An Emissions Scandal Decades Before Volkswagen

Dieselgate was a watershed moment for the automotive world. In 2015, Volkswagen was caught cheating on emissions rules by building cars that acted clean when tested, but polluted heavily the rest of the time when out in the real world. The Germans weren’t the first, though. Nope, one previous example occurred in the 1990s, and it involved General Motors.

You might have enjoyed our story about Ford’s innovative methods of meeting emissions standards back in 1975. A hunt for similar efforts at the General led me to a darker narrative around illicit “defeat devices.” This term became a hot-button topic after VW’s folly, and referred to a tool used to circumvent emissions regulations.

It sounds like some cool bit of hacker kit you’d use to steal millions of dollars when you’re cracking into a mainframe, but the term actually dates back much further. In fact, since the dawn of emissions regulations, the EPA has been hunting for sneaky little devices that work around those regulations. In 1993, that’s what the EPA believes it found when it was tinkering with some of the General’s premium machines.

Cool It Down

It all kicked off in a routine lab test in 1993. The EPA happened to have some Cadillacs on the bench. Much to its surprise, the vehicles tested were spitting out up to 10 grams of harmful carbon monoxide a mile. This was well over the legal limit at the time, which stood at a mere 3.4 grams per mile. Further investigation revealed something curious. As explained in a contemporary EPA press release, The Cadillacs were exceeding the official limits under a very specific condition: anytime the climate control system was in use. Before long, the Justice Department felt like it had a case, and the matter hit the courts.

The matter concerned Cadillacs fitted with the 4.9-liter L26 “High Technology” V8 engine. This included a wide range of models built from 1991 to 1995, including the 1991 to 1993 Cadillac Seville, the 1991 to 1995 DeVille, the 1991 and 1992 Fleetwood, and the 1991 to 1993 Eldorado. A population of around 470,000 cars were caught up in the furor by the time the matter came to a head.

GM had a great explanation, though – or some might call it an excuse. The official line was that back in 1990, Cadillac was having trouble with a number of models. Customers were finding their vehicles were stalling out when running the heating or air conditioning. Thus, GM implemented a simple fix and retuned the electronic fuel injection system on certain models, setting up the engine computer to supply more fuel while the HVAC system was on. Unfortunately, this richer fuel mixture also greatly increased carbon monoxide emissions – no surprise, given CO is a common byproduct of incomplete combustion.

It’s an odd story. Generally, you’d expect a major automaker such as GM to have thoroughly tuned and tested the engine controls prior to releasing the vehicles to customers. This would include test-driving the vehicles under a variety of real-world conditions, including with the heater or air conditioner running. You’d also expect an automaker to verify the car was emissions compliant under a wide range of conditions, including operation with the HVAC system in use. And therein lied the crux of the matter.

Back in the 1990s, standard EPA test cycles weren’t as rigorous as they are today. Cars used to be tested on regulated “city” and “highway” driving cycles, with the climate control turned off. Thus, if one of the given Cadillac models was tested under a typical regime, it would show up as compliant. Flick on the air conditioner, though, and the richer fuel mixture would kick in, and CO levels would shoot right up. This meant that Cadillac was building cars that passed typical tests, but emitted much more pollution when out on the road. It may seem somewhat like what VW did years later, though it’s worth noting that Cadillac wasn’t trying to detect when it was being tested, and it wasn’t changing its emissions solely when under the microscope.

When the EPA found out, the matter went to court. The EPA argued that GM knew exactly what it was doing, and that it had effectively built a “defeat device” to skirt around emissions regulations. It stated that the company would have known the tuning change would have increased emissions output. By 1995, the EPA stated that the trick had led to the illegal release of 100,000 tons of excess carbon monoxide pollution.

"Carbon monoxide can cause cardiopulmonary problems and can lead to headaches, impaired vision and a reduced ability to work and learn. These so-called defeat devices are not just paper violations, but result in real increases in emissions that affect real people." - Attorney General Janet Reno.

The case didn’t exactly go GM’s way. The automaker spent $45 million to settle the charges while refusing to admit guilt. These included allegations that GM had sold vehicles that were non-compliant with the Clean Air Act, that it had sold vehicles fitted with illegal defeat devices, and that it had failed to accurately explain what it was doing to the relevant authorities. GM had also allegedly installed chips that made the tuning change in certain 1991 model year vehicles after they were sold—which the EPA alleged counted as tampering with vehicles to circumvent emissions standards.

At the time, it was the largest case ever brought by the justice department under the Clean Air Act. $11 million was paid as a fine, with $25 million allocated to recall and refit affected vehicles. A further $8.75 million was dedicated to offsetting the increased emissions from the affected vehicles.

Still, GM remained unrepentant in the wake of the judgment. “It was not in the rules, not in the regulations, it’s not in the Clean Air Act,” GM spokesperson Betsy Hemming told the New York Times in the wake of the settlement. GM’s position was that the regulations had given them no reason to test their vehicles with the climate control running. The automaker put the whole situation down to the fact it was simply playing by the rules of the EPA’s standard test cycles. “This is a matter of interpretation of current regulations regarding the complex issue of off-cycle emissions,” said Dennis Minano, GM’s then vice president of corporate affairs.

Of the $8.75 million offset fund, GM agreed to use the money to support cleaner air initiatives to help repair the damage that had been done by the heavily emitting Cadillacs. This was to potentially include things like buybacks of highly polluting vehicles like older school buses, and replacing them with newer models that ran cleaner and more efficiently. These measures were targeted to Phoenix and Maricopa County in Arizona, and Southern California, as these areas were suffering some of the worst air pollution in the US at the time.

As later approved by the Justice Department in 1996, GM funded projects in California, Arizona, Connecticut, New York, Massachusetts, and New Hampshire. The measures also saw GM providing electric vehicles for government agencies, and saw the automaker fund the purchase of electric shuttles and pick-up trucks for use at Boston’s Logan International Airport. The airport also received funds to convert ten tow tractors and a conveyor loader to electric drive.

All in all, it was believed that these projects would cut annual carbon monoxide emissions by 2,400 tons, hydrocarbon emissions by 300 tons, and nitrous oxide emissions by 175 tons. These benefits would stack year on year, but it would be some time before they made up for the 100,000 tons of excess carbon monoxide emitted by the questionable Cadillac fleet.

From the EPA’s perspective, this case was a slam dunk. It mandated certain emissions standards, and specified a test cycle to measure if cars lived up to them. The test was merely a functional tool, as far as the EPA was concerned—not the be-all and end-all of compliance. Passing the test was important, but no guarantee a car was compliant. Meanwhile, GM had taken the opposing stance—that any car that passed the standard tests was fine and legal to sell. The latter attitude is often one that works quite well in motorsports, but it’s not a winning strategy when it comes to emissions compliance.

It’s not quite the same the hurdle Volkswagen would trip over decades later. GM’s attitude was that the EPA didn’t test emissions with the AC on, so emitting more in this regime was surely allowed. Volkswagen, on the other hand, set up its vehicles to specifically detect when they were under test, and artificially reduce emissions. The latter was a far more egregious example of a defeat device, whereas GM’s method fell much more into shades of grey.

Still, had VW executives examined the million-dollar disaster that had befallen GM, the company might have been less eager to press its luck. Volkswagen was caught in much the same way, too, albeit by private researchers rather than the EPA itself.

Ultimately, automakers, and the engineers within, should take this as a cautionary lesson going forward. Just because you can sneak past the test, doesn’t mean you’re doing the right thing. Still, one suspects that Volkswagen won’t be the last automaker to try and slide under this tantalizing limbo pole.

Image credits: GM, Cadillac, Volkswagen