Re: What motivation car manufacturers ?
Can't see anyone in the EU getting tough with car manufacturers, can you?
This is simply because in the USA the oil lobby has nearly unlimited power. Anything that leads to lower consumption of cheaper fuel (f.e. diesel) is pushed back significantly. If you unwind the whole trail all the way to the money originating point you will be surprised to find that some of the clean air acts had petrol money in them. Once you do the math you see that you actually end up increasing the fuel consumption in order to satisfy some of the more odious requirements, such as for California. From there on it is no longer surprising.
This does not mean that the whole lot who use "test facilities" on Bosch ECUs (it is funny how Bosch got off the hook in all cases) are not guilty as hell. Of course they are. However, the specific cases brought to the attention of the general public and lobbied against are based on money interests. They are not because of some "extreme benevolence" of the EPA and Americans. Just the opposite.