Petroleum Testing
Density
The density of a fuel is a measure of the mass per unit volume. It is used in fuel load calculations since weight or volume fuel limitations (or both) may be necessary according to the type of aircraft and flight pattern involved. In most cases, the volume of fuel which can be carried is limited by the tank capacity. To achieve maximum range, a high-density fuel is preferred because it provides the greatest heating value per unit volume of fuel.
The heating value per unit mass of fuel, however, falls slightly with increasing density so that on occasions where the weight of fuel which can be carried is limited, it can be advantageous to use a lower density fuel.