OK, even though no one probably cares, this VW thing is nutso, and I think even non car-people will have some interest it's so brazen.
Short version: VW cheated the diesel emissions testing by figuring out a way to make the emissions control only turn on DURING THE TESTING FOR EMISSIONS. Outside of that, the emissions control system is severely limited, making the NOx emissions 10 to 40 times higher than the limit in every instance other than when it was being tested by the EPA. So it passed the test, but every single vehicle is running around violating the limit 100% of the time it's running. They're screwed.
Long version: Modern diesels (pretty much all of them other than VW's car diesels, anyway) meet the emissions standard by using a fluid (Diesel Emission Fluid, or DEF...it's Urea and water...essentially, cleaned up urine) sprayed into the exhaust to catalyze Nitrous Oxide (NOx) into Nitrogen and Oxygen, since NOx is a huge polluter in diesel emissions. This fluid has to be refilled (not sure how often). Since VW mainly sells passenger cars in the US, ain't nobody wanna mess with that, so VW was motivated to pass emissions testing without DEF. You can do it, but your power or mileage will suffer. Again, VW trying to create demand for diesel cars in the US was motivated to overcome it. We thought they had, but no one knew how...until now. The emissions testing is pretty specified to make it 'fair' and predictable for car companies to design for. Problem is, VW programmed their Engine Control Unit (ECU) with an algorithm to monitor the specific conditions in the test...one of them probably involves the front wheels turning, but the back not...conditions on a Dynamometer during the testing, which would never exist in the real world, other than tuners who might independently dyno their cars to see how much power they can get out of them. Students at West Virginia were testing the cars and found the anomaly, but didn't know why. The EPA started asking questions, and VW fessed up.
Cheapest buzz of the semester. I like donating because you never know who/how you are helping someone, but you've done something good.
