All new USA cars need to be
All new USA cars need to be SULEV and many models have the option of PZEV. I thought those cars had very low emissions? I checked out the exhaust on a new PZEZ Subaru Outback when cold, at first there is a bit of a smell, but within 30 seconds the exhaust got hot and the smell went away, so as far as my nose was concerned only CO2 was coming out of that tailpipe after the CATs started heating up.
I think all SULEV cars come with 2 catalytic converters but I could be wrong.
I just wonder what is the next requirement the EPA or CAFE will require for gas cars, and the challenges it may bring to keep MPG high.
I'd suppose it would be PZEV mandatory.