USA emissions laws are always hamfistedly stupid. Just look at air injection pumps on older engines from the 80's/90's. The emissions laws were met by simply d

USA emissions laws are always hamfistedly stupid. Just look at air injection pumps on older engines from the 80's/90's. The emissions laws were met by simply diluting the exhaust stream with air pumped into the exhaust manifold. The EPA knew this but as long as the check box was checked the bureaucracy was appeased. EPA Diesel emissions are also handled in an equally idiotic way: When a new EPA diesel mandate went into effect, it is a strict cut off for sales of ALL non compliant engines lest manufactures pay fines (ask CAT). When EPA 2006 was going into effect mandating the particulate filter, 2007 truck sales took a hard dive. No one wanted to buy new and therefor "untested" engine technology to power their business. Europe on the other hand was smart: when a new emission tier goes into effect, the previous tier is still available, but at a higher cost! This allows companies to continue to buy trusted technology at the cost of paying a higher yearly registration fee which is a sort of pollution penalty. The new tier engines have standard registration cost so it provides a monetary incentive to encourage adoption. Compare this to the "hold a gun to everyone head" policy of the stupid EPA.