Expert: Dave Russell - 11/15/2006

Question
Good day Mr. Rusell,
I would just like to ask bout the difference of the three (diesel, unleaded and leaded gas?) and how each of the affect air pollution.

Answer
all 3 are hydrocarbons, so all 3 produce the same types of pollutants, except leaded gas. Gasoline does not contain Tetraethyl lead, but the automakers and the petroleum companies decided to add it to help reduce engine knock and give better performance with a less refined gasoline (lower octane). Leaded gas (now banned) produces particulate lead which is a poision to many systems, including ours.
Diesel is a less refined product of petroleum. As such it takes a different type of combustion system, the diesel engine. Some of the newer diesel engines are quite good at producing low amounts of NOx,some better than gasoline engines.  Diesel fuel is higher weight and contains more energy than gasolines. Diesel engines tend to produce more particulate material than gasoline engines.
Hope that helps.