Long before hybrids became the hip way to cut down on fuel costs, diesel engines were the road warrior’s only option.
Diesel fuel is a kind of gasoline refined from crude oil or petroleum. In oil refineries, crude oil is heated, and various hydrocarbon molecules are extracted to create fuel. Diesel is much heavier and oilier than gasoline and evaporates much more slowly. It’s often referred to as “diesel oil” because of its consistency.
Diesel fuel has approximately 18% more energy per unit of volume than gasoline. It also takes less refining to make diesel. In addition, diesel engines are actually more efficient than gasoline engines. As a result, people with diesel engines enjoy better gas mileage.
On the negative side, diesel contains more particulates (particles of soot) than gasoline, which cause smog. And it goes without saying that diesel-friendly stations aren’t nearly as common as those that pump ol’ 87 octane.
There are a lot of simple ways to improve the efficency of your car. These energy tips from About.com are a smart place to start.