It's kind of amusing to contrast the comments here vs a thread on the GDPR. Here many of the comments are along the lines of "it's not fair how California can enforce a law outside it's borders" but the GDPR ones were all "How does the EU hope to enforce this on american companies".
While there are some differences for diesel engines due to the way it is measured (in favour of diesel engines in the eu), the Euro 6b standard is on par with the californian standard for the most part.
The comparison is not easy though as the european standards focussus on hydrocarbons and the californian on NOx.
It's kind of amusing to contrast the comments here vs a thread on the GDPR. Here many of the comments are along the lines of "it's not fair how California can enforce a law outside it's borders" but the GDPR ones were all "How does the EU hope to enforce this on american companies".
While there are some differences for diesel engines due to the way it is measured (in favour of diesel engines in the eu), the Euro 6b standard is on par with the californian standard for the most part.
The comparison is not easy though as the european standards focussus on hydrocarbons and the californian on NOx.