By Marc Hoag, Love of all things cars and automotive. Love Top Gear.
The utterly mind-blowing, inexplicable implosion of Volkswagen, the number 1 car company (by sales) in the world, has shocked not just the entire auto industry, Top Gear fans, and auto enthusiasts generally -- never mind VW owners -- but every person on the planet not living under a rock as well. This isn't just a big deal with respect to the auto industry; it isn't even just a big deal with respect to the environmental harm such deceit has surely caused; it's a big deal with respect to the general trust -- or lack thereof -- consumers should place in the companies with which we deal on a daily basis.
First, a quick primer on what the heck just happened, and what it all means.
What the heck just happened?
It appears that a certain model of diesel engine used by VW was unable to meet the incredibly stringent emissions laws of the US, and so a cheat was implemented to work around it. Basically, the engine software could detect when the car was subjected to emissions testing -- i.e., strapped to a dyno, sensors attached, etc. -- and it (probably) retarded engine torque (and thus power, as power is simply a function of torque, and with it, fuel efficiency as well) in an effort to reduce emissions to the required level and successfully pass the test.
''In short, a software cheat choked the car to reduce emissions while testing, and allowed the car to breathe freely when not testing.''
Then, when the testing was completed, the software would revert the car to its ordinary operating parameters with increased torque and improved gas mileage, along with exhaust fumes far above the legal limit. In short, the software choked the car to reduce emissions (and power and fuel efficiency) while testing, and allowed the car to breathe freely -- producing more power, with improved fuel efficiency, and of course increased toxic emissions -- when not testing.
What are these emissions, exactly?
The exhaust vapors of automobiles are pretty nasty stuff. As a result, gas (petrol) and diesel cars alike have complicated systems to cleanse as much of the toxic chemical compounds as possible before they exit the exhaust pipes. All things being equal, there is a cost associated with such cleansing apparatus, typically manifested in the form of reduced power and gas mileage.
There are two main chemical compounds that really matter: CO2 (carbon dioxide) and NOx (basically, any oxides of nitrogen, e.g., NO and NO2). While CO2 is a huge contributor to greenhouse gases, NOx wreaks havoc on air quality, and is the primary culprit in the formation of smoggy air. What are the legal requirements for diesel engines in the US? The US is notoriously strict on emissions -- whether diesel or gas -- and our threshold is a staggering 10 times lower than in Europe (excluding the new Euro Emissions 6 (EU6) standards), or roughly 0.025 g/km NOx.
VW's diesel engines produce a whopping 40 times the legal limit of NOx.
So how much NOx do VW's diesel engines produce with the software cheat?
A whopping 40 times the legal limit, or roughly 1 g/km NOx. To put it another way, a 100 km drive -- roughly 62 miles -- would produce a staggering 100 g -- basically one 3.5 oz shot glass -- worth of noxious NOx.
How are these emissions reduced?
There are two methods in use today, the most common of which is a urea-based solution which serves as a final cleansing agent just before the exhaust exits the vehicle. It works well, but the downside is that the urea solution needs to be replaced every so often, typically when performing an oil change. It's also a somewhat bulky, cumbersome apparatus, and ads several hundred pounds of weight to a vehicle. You might call it a sub-optimal hack solution, then. But it works. And for the emissions gods, that's all that matters. The other method is effectively a "trap" system which dispenses with the urea solution entirely and simply collects the offending chemical compounds before they exit the vehicle.
The trap mechanism sounds great; why would any car manufacturer ever use the urea solution method?
Simple. The trap mechanism sounds great, but, well, isn't great at all. Indeed, if you look at all the other car manufacturers that sell diesel in the US -- Mercedes, BMW, Porsche, Audi, and a handful of American cars -- they use the urea solution instead. They couldn't get the trap solution to work.
Why didn't VW just use the urea solution?
VW did use it for some of their larger diesel engines in use in their larger vehicles. But for their smaller cars -- Beetle, Golf, Jetta, Passat, Audi A3 (VW owns Audi), and, in Europe, certain Seat and Skoda cars -- they used a smaller 2.0 liter diesel engine with which, presumably, they wanted to save weight and complexity.
''VW wanted to offer the simplest solution possible, i.e., something without the urea solution; something you never even had to think about.''
Also, although the replacement of the urea fluid is a simple thing performed for free by the dealership, and almost always concurrently with an oil change so that it doesn't in any way inconvenience or otherwise adversely affect the car owner, it just seemed like an added layer of maintenance, just another thing that had to be done. So for the smaller, less expensive, more mass market cars, VW wanted to offer the simplest solution possible, i.e., something without the urea solution; something you never even had to think about.
Who else uses the trap method instead of the urea solution?
To my knowledge, nobody: no other car manufacturers have managed to design a potent, high gas mileage diesel engine utilizing the trap method capable of meeting the stringent emissions regulations.
So VW was the only car manufacturer to pull this off then?
Yes. Except that they didn't really pull it off at all. It really was too good to be true. It didn't work. Hence the software cheat.
But did the ploy work at least?
Did VW sell more diesels in the US than other car manufacturers? Absolutely. VW has sold more diesel cars in the US than any other car manufacturer. The combination of hybrid-calibre fuel efficiency plus strong, torque engines, immensely far cruise ranges, and trouble-free maintenance, not to mention bullet-proof, forever-lasting engines, finally started to catch on and overwrite diesel's dirty, smelly past which effectively ended in the US in the 1980s.
And what kind of MPG numbers are we talking about?
A diesel VW Golf TDI is rated at around 43 mpg freeway, good for an impressive 550 miles of range, and offers an incredibly strong 236 lb/ft of torque which has no problem masking the seemingly tiny 140 hp.
''
Weirdly, real-world gas mileage (and thus, range) was significantly higher, often in the mid- to high-50 MPG, offering a staggering 700 miles of cruise range, even at 70 mph. But weirdly -- and perhaps now we know why -- real-world gas mileage (and thus, range) was significantly higher, often in the mid- to high-50 MPG, offering a staggering 700 miles of cruise range, even at 70 mph. ''
If indeed the software cheat functioned by retarding engine power and/or increasing fuel consumption, then this would explain the discrepancy between the EPA MPG claims and the oft-cited real-world driving results by diesel VW owners.
Ok so what's this new theory? As of today, VW's CEO Martin Winterkorn has just resigned, and although effectively admitting guilt, the claim from VW top brass is that they simply didn't know. First, even if they didn't know, they should have known. Still, it's a curious thing worth pondering. Is it really possible they didn't know?
VW's past, present, and future, have always been about diesel, not hybrid Diesel is by far and away the fuel of choice for vehicles in Europe, largely due to the stupendous taxes levied on gas (petrol), which makes diesel relatively cheap in comparison. That, and all things being equal, a small (modern) diesel engine will usually offer a better driving experience than a comparable gasoline engine: vastly more torque offers immediate acceleration from a stoplight and during passing maneuvers around town; around 20-30% greater fuel efficiency; engines that will go hundreds of thousands of miles without failing; and, best of all, diesel vehicles are typically less expensive than comparable hybrids. Win, win, and win, then.
VW has been floundering in the US for quite some years, and with the spiked demand for more fuel efficient cars, has been hell bent on making a name for itself as a more economical -- and better driving -- alternative to hybrids with its new so-called "Clean Diesel" TDI-badged cars. Combined with the legendary "German driving dynamics" offered by even the most pedestrian of VW's offerings, it appeared VW's strategy was working.
''VW's top brass was adamant that its engineering team figure out how to make the urea-free "trap" mechanism work while all others had failed.''
There was just one problem: the icing on the cake was to be VW's urea-free "trap" mechanism, a seemingly impossible engineering accomplishment that VW -- and VW alone -- was determined to master while all others had failed. VW's top brass was adamant that its engineering team figure out how to make it work.
Except that VW couldn't make it work. Try as they might, VW's brilliant engineers simply couldn't make the trap mechanism work as well as the urea solution to capture or cleanse those noxious vapors produced from diesel combustion. Not by a long shot; indeed, as has since been reported, these cars have been belching out 40 times the legal limit.
"Vee must cheat the system. I know! Let us write some software to trick the emissions test! Yah! Das ist eine gute Idee!"
But still the question remains, how could VW have authorized such deceit? Can you imagine a bunch of VW executives sitting round a table saying "Nein! This is not good enough! Ok then, fine: vee must cheat the system. I know! Let us write some software to trick the emissions test! Yah! Das ist eine gute Idee!"
Fake it until you make it?
That's a comically absurd scenario to contemplate, so I'd like to propose an alternative: what if the engineers had no choice? What if VW was pressuring them to such a degree -- with threat of losing their jobs even? -- to solve the emissions trap mechanism that, in a last ditch effort of frustration with what was apparently a physically impossible engineering task to begin with, they basically threw their collective hands up in the air and said "Scheiße! This is impossible, it cannot be done ... ok screw it, let's just fake it."
''What if the engineering team threw their hands up in the air and said "Scheiße! This is impossible, it cannot be done ... ok screw it, let's just fake it."
Isn't it at least within the realm of possibility that VW executives did not in fact know what was going on, and it was merely out of an act of desperation under threat of losing their jobs that the engineers finally just caved in and did whatever they could?
Isn't it possible that the engineers simply cheated to appease a totally irrational demand by VW and to keep their jobs?
Obviously, this wouldn't in any way insulate VW executives -- again, even if they didn't know, they certainly should have known -- but it's a fascinating theory to consider, and certainly at least gives pause to wonder if there is in fact a limit to how hard one should push their team, especially when the goal is essentially impossible. Then again, Elon Musk seems to have accomplished the seemingly impossible again (Tesla) and again (SpaceX) and again (SolarCity), without running afoul of any laws or regulations.