I’m aware that EU-spec cars are equipped with gas particulate filters (GPF/OPF) which mute sound compared to cars exported to the States and Canada. Does anyone know if Japan-spec 992s have this OPF?
Secondly, does the filter affect performance/top-end acceleration at all?
Not sure but I think US cars have opf, just not monitored. I know my 718 does.
Yup.