On Sun, 15 Dec 2019 12:31:21 +0100, Axel Berger wrote:

> A much higher efficiency is reached by using lean burning engines in the
> first place, but then you tend to maximise nitrous oxides and there's no
> easy way to reduce them.
>
Indeed, and NOx seems to be the prime concern of those interested in
cleaning up urban air, now that diesel smoke has mostly disappeared.

IIRC there was concern about heavy metal dust pollution from catalytic
converters, but that seem to have ben  kicked under the table as well.


--
Martin    | martin at
Gregorie  | gregorie dot org

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