That's why most of the engine producers are working flat out to meet the emissions requirements.

The fuel companies are also striving to clean up the fuels but the biggest problem at the moment seems to be the particulates.

I see an "exemption" coming along in the future.
Also, it would be impractical or unreasonable to backwards enforce this.  That big Scania thundering along the M25 could not be forced or required to comply with future legislation.

Afterall, you can't get 4 star leaded fuel anymore, but there's plenty of cars still around that were designed to use it.

Those particulates are problematic, without any doubts.
My grandmother swore by zinc and castor oil cream. But she swore by most things to be honest, when she wasn't sparring in the ring down at the Miners Welfare she was knocking back the Fed Best in the snug with the WI.
Tucking into a steak and kidney pud from grandma had the same sweaty feeling as a scene from The Deerhunter.
I believe that there are better preparations on the market now than zinc and castor oil cream. Muller Rice, for instance.
H

H, it would be good to know which preperation you would most highly recommend, so it begs the question.........what Preperation H??