[Bartweiss]

I do think that manipulating a purely instructive measure is less extreme than manipulating a compliance test; consumers can seek alternate tests and reviews, but the state emissions test has special status even if a dozen other tests give a different result. That said, I believe Energy Star ratings affect tax rebates and electric bills, and they're required to be printed on products - so that's not really an arbitrary test.

There are other differences here too, I think. The water heater trick is passive manipulation that stays in place at all times, which limits how far from "real" performance it can get. And per the story, it seems more like "teaching to the test" than "cheating". That is, Volkswagen consciously moved away from the mandate outside of testing. The water heater was (potentially) as energy-efficient as they could design, with the test score manipulated on top of that.

None of that makes it harmless - if "as good as you can make" doesn't hit standards without manipulating them, that's still a problem. But I do find it less galling than "intentionally worsens emissions outside the test bench".

[Gibbon1]

The flip side of the water heater test is, you could game the test the other way too. Making your water heater look worse than it is. Would you do that? No.

The difference between the water heater and VW is the water heater manufacturer is providing a representative sample. And VW was not. It'd also be dubious to say that the water heater company is acting in bad faith. Where VW's bad faith rose to the level of criminal. On the other hand Volvo appears to be acting in strictly good faith.

Bad faith for a crash test would be crafting a silver plate model for testing. Reminds me that's what my uncle said the power supply manufacturer he worked for did.