California I think the question was what country has the toughest emission standards.
Countries with some of the toughest emission standards include Denmark, Sweden, and Switzerland. These countries have stringent regulations in place to control emissions from vehicles, industries, and other sources to protect the environment and public health.
United states
They are based on the California State vehicle emissions standards, which are the toughest anti pollution requirements in the USA. Vehicle/ after market manufacturers produce cars and performance components to meet the Californian emission standards. Hence, fifty state legal..
Cali has the toughest emission laws in the USA, and as with other states, they have to follow fed guidelines, but can impose even more higher standards above and beyond the feds, and Cali does, so I would suggest that you bring your vehicle up to Cali standards, or it will be just a matter of time before they test it.
Foreign car manufacturers will have to meet those emission standards on cars they export to the U.S.
Currently Euro2, according to ECE R83
No not as long as they meet the smog emission standards and the safety standards set by the state.
Depends on what sort of vehicle your driving, but most of them are to EU regulations. You can check them out at this website; http://www.dieselnet.com/standards/au/ and because you wont know what the EU standards are, you can check them out here; http://www.dieselnet.com/standards/eu/ld.php But can't seem to find any recent emission standards on motorcycles. Hope that helps you out anyways. ;)
Imported motor vehicles are subject to U.S. safety standards, bumper standards, and air pollution control (emission) standards. Most vehicles manufactured abroad that conform with U.S. safety, bumper, and emission standards are exported expressly for sale in the United States; therefore, it is unlikely that a vehicle obtained abroad meets all relevant standards. Be skeptical of claims by a foreign dealer or other seller that a vehicle meets these standards or can readily be brought into compliance. Nonconforming vehicles entering the United States must be brought into compliance, exported, or destroyed.You need to be sure that you have fully researched taking a car to the USA - you can then look into shipping via either container or RORO
The skyline doesn't reach US emission standards.
Tighten emission control standards for factories and automobiles.