while not defending the purposeful fraud on VWs part the cars are still less polluting than the generation they replaced. That number cited by the MIT paper is

while not defending the purposeful fraud on VWs part the cars are still less polluting than the generation they replaced. That number cited by the MIT paper is so low as to be not something that can actually be corrected for. Great compilation of California pollution regulation that applies https://www.dieselnet.com/standards/us/ld_ca.php#leviii https://www.dieselnet.com/standards/us/ld_ca.php#leviii