[VAC] Re: Vintage haulers and unleaded fuel

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxxxx>]

The oil companies can make high octane gasoline without lead additive
but its expensive, and there's a lot of product from the refinery that's
less saleable. Making lower octane gasoline and raising its octane
rating with tetraethyl lead is most productive.

Its exhaust gas RECIRCULATION that is used to lower combustion
temperatures in the gas engine. Combustion temperature is lowered to
reduce the production of nitrogen oxides. There's a lot of nitrogen in
air and with efficient high temperature combustion NO2 is a common
product which is rather corrosive and hard on the environment when it
gets concentrated in smog.

Gerald J.