WRT vehicle emissions. Right now, all cars sold in the US are sold under the LEVIII laws for California and the other Green States, and Tier 3 for the rest of the US. And the way Tier 3 rules are written, all cars sold in the US right now are LEVIII compliant. And they will following the CA rules for the foreseeable future.
This is for HC, NOx, and CO.
When it comes to CO2, that really has not been settled 100% if California gets to have the rules or not. And here's the paradoxical part- GM, Toyota, and the rest are likely arguing for the US standard for CO2, and RIGHT NOW, that STILL is Obama era rules. While dumpy has said he will roll them back, that has not happened, and is very, very unlikely to actually happen. The administration needs hard science to prove that the rules can be relaxed, and we know that's not going to happen.
So it *seems* as if some of the car companies are siding with dumpy, but the *current* reality is that they are siding with Obama over California.