When it comes to fuel for vehicles there are two categories. One is gasoline, the other is diesel. Most people are pretty familiar with gasoline but are much less familiar with diesel. For instance, you might not know that there are different kinds of diesel.
Diesel #1 isn't as commonly used as other forms of diesel. For one thing, it doesn't provide the same amount of energy that other kinds of diesel fuel does. It also tends to be more expensive. One big difference between #1 and #2 is that liquid paraffin wax isn't added to diesel #1. The benefit of this is that it doesn't tend to gel in the cold; however, the paraffin is used as lubrication for the engine.
Diesel fuel #2 is what you will find if you pull into your local gas station. It has paraffin wax added to it, so it will lubricate the engine well. Diesel #2 has more energy in it than does gasoline, which is why some people prefer to have a car that has a diesel engine. It's also why most semi-trucks take diesel, they get more bang for their buck. One significant problem is that it can start to thicken and gel when the weather gets cold, which can cause problems with fuel filters. However, winterized diesel can avoid that problem.
This diesel is meant specifically to be used in colder weather. You will generally find it in areas where the temperature routinely drops below freezing and stays there during the winter. Usually winterized diesel is made by adding a little bit of D1 to some D2. The #1 thins out the paraffin, making it less likely to gel. Sometimes winterized diesel is also made by adding a little bit of kerosene to the D2, which also thins out the paraffin.
Biodiesel is starting to be more popular and can even be found at some gas stations. Biodiesel is made of things like old cooking oil. There is a process that can make a usable fuel that will run an engine. People can actually make this kind of diesel at home if they decide to and if they have the right kind of equipment.
Just like gasoline, there are different kinds of diesel fuel. Diesel has gotten a bad rap in the past, but most of the things that have given it that bad reputation have been changed. For more information, seek out diesel depots like http://unitedoil.net.