Internal combustion motors pollution

What fuel used in internal combustion engines contaminates more? I generate this concern, taking into account the current problem we have on the entire planet with pollution. And let's not hope that the changes begin from governments, rather, let's start the change from our concept and knowledge, we generate another way of thinking and more from the things we like how vehicles and machines are. I await your answers.

To my opinion is gasoleum the dirtiest fuel used in engines (also fuel-oil) for the amount of particles and soot that emits in combustion, despite the new systems that apply (EGR, FAP, etc.) do not manage Nox to the atmosphere ... Then there is the issue of the degradation of oils and catalysts or anti-particle filters (FAP) that to see what treatments give them ... no matter how much companies "draw it" beautiful and simple, it is not really. Summarizing: oil is what has always been.
From my ignorance I think that the most ecological could be any fuel that does not come from hydrocarbons, but neither does I defend the electric motors, since the electrical energy we also have to produce it or by nuclear energy, thermal central (we are already burning fossil fuel ..) to others of the problem that the batteries pose in terms of the recycling or production of these ... in short, that I do not see it, I do not see it. Interest and your way of thinking about this great problem that almost no goovrese seems to want to solution or put anything on your part. I encourage all who think like you to participate in this topic. Greetings!!