In article ,
PC Paul wrote:
I remember the concept well - lean burn engines were coming along well
but only the European manufacturers had engines close to production
which could meet the proposed emissions, so US pressure was applied to
make cats the only allowed solution...

Or something.

There is no legal requirement for a cat. - merely to pass the emissions
regs. How it is done doesn't matter. And some engines get very close
without a cat. IIRC, the problem with lean burn engines is high NOX output
- although CO can be low. CO2 is also lower, but this isn't tested.

--
*They call it PMS because Mad Cow Disease was already taken.

Dave Plowman London SW
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