That's exactly what I've been trying to figure out. Why would the US discourage diesel frugality by making them more expensive to import, especially when some of them can get better mileage that their beloved hybrids.
I don't think diesel is more harmful to the environment than petrol, the main issue is that diesel is more expensive there.
I don't see how marketing a 2.0l diesel as a 28d will create a paradigm shift on how they feel about diesels. Those who care about the nomenclature would definitely know how big the engine under the bonnet is, and those who don't generally wouldn't care less if it was called a 320d.
Weird to say the least.