3 ms·

I don't think that's right. I believe this is the relevant EPA regulation: https://www.govinfo.gov/content/pkg/CFR-2004-title40-vol17/pdf/CFR-2004-title40-vol1

• Aurornis 5mo ago
  > This mentions emission limits but does not require a catalytic converter IIRC, technically if the vehicle meets emissions limits without a catalytic converter then it doesn't need one. The emission limits are set such that a catalytic converter is required to meet them. They don't have to say "catalytic converter required" but the targets are chosen so that a catalytic converter can reasonably achieve them. If the laws simply said "catalytic converter required" then manufacturers could put a tiny little square of catalyst in the exhaust and call it a day. Formula 1 isn't the only place where rules have to be written explicitly to avoid clever workarounds.
  • mulmen 5mo ago
    > Catalytic converters were required You claimed they were required by law, but they weren’t. Now you claim they had them anyway, but I can find no evidence of that either. Do you have some evidence that 1988 GMC 6000 trucks had a catalytic converter from the factory? I can find nothing online to support that claim.