[Redbob]

"AFAIK car emissions are still only regulated during the LA City Traffic driving cycle at low and “high” (Denver) altitudes. Not on the highway except for fuel economy on the highway cycle."

Wrongo, bwana: emissions are regulated at all times; they're only "tested" on a driving cycle, but you sure as the dickens can't make the emission control strategy only function during the test!

American Motors tried that back around 1970 and got their you-know-whats whacked big-time.

[Paladin2]

Then please forward the standards/requirements....

Heavy Duty Trucks have testing that is independent of drive cycle (engine dyno testing at various parametric operating points).