Unlike popular belief, oil does not come from the remains of dinosaurs, rather from the silica based life-form called diatoms. Diatoms live in the top few meters of oceans and lakes and are able, unlike people, to convert sunlight into energy.
In order to remain afloat and to store the energy they soak in, diatoms create an oil substance. But in order to use this oil to fuel your car it needs to be condensed in the ground for millions of years. It takes about a 20 metric tons of these these guys to make one liter of gasoline for your car.