Which one acually produces more pollutants. I need this for a school paper.

That's not a simple answer.

It depends on what is considered a "Pollutant".

Typically, in a gasoline powered engine, the major pollutant is NOx's. That's Oxides of Nitrogen. Also there is CO2, CO, water, soot, and a few other things I can't remember.

A diesel produces much of the same byproducts but in different concentrations. Some are higher, some are lower.

The major differance in "pollutants" between Diesel vs. Gasoline, is the efficiency of a diesel is much higher than an equalivant sized, (power output), gasoline engine. So one is able to produce the same power output with less energy input.

So, as a person who has an Environmental Degree, this is my opinion only;

In the United States, there are far more gasoline based internal combustion engines than there are diesels. The byproducts of combustion from a gasoline engine is more harmful, (this is a relative term), than the byproducts from a diesel. So, using that logic, Gasoline engines pollute more than diesels. However, ANY byproduct of combustion tends to be detrimental to O2 breathers. That also includes buring coal, burning wood, burning anything with Carbon.

That is the price Human's pay for surviving in the world. There are over 6 billion people on the planet and even if you could rearrange them to minimize the use of energy, to have little of an impact on the environment, about 5 billion of them would have to leave.. To keep large populations in areas that they are not naturally adapted to will need energy. We gave up our built-in fur coats long ago.

To put things into perspective, 1 volcano eruption causes more Pollutants to be put into the atmosphere than what man has done in the past 100 years of industrial revolution. And most of the pollutants are way more toxic to humans than humans tend to create on a day-to-day basis.

That probably didn't help you much on your paper. But you may want to modify your thesis a little.

I've had this discussion with folks some and would love to see some good sources on the subject.