Regulations are obeyed and enforced by humans. There’s a general expectation that common sense is applied, which is hard to define but “you know it when you see it”.
“The engine will fundamentally perform differently when you’re testing it because it will detect the test” is not common sense and is not a reasonable interpretation of how to comply with the rules.
I agree that a better method would be to attack sensors to a random (and ideally, concealed from OEM) sample of cars and charge automakers per unit of detected emissions. That would force them to optimize for real world driving, which is much harder to game.
“The engine will fundamentally perform differently when you’re testing it because it will detect the test” is not common sense and is not a reasonable interpretation of how to comply with the rules.
I agree that a better method would be to attack sensors to a random (and ideally, concealed from OEM) sample of cars and charge automakers per unit of detected emissions. That would force them to optimize for real world driving, which is much harder to game.