Abstract: Vehicle operating conditions are computed and the instant variable cost of operation is displayed, enabling operators to learn to operate the vehicle in ways that maximize value, minimize fuel consumption, and reduce or avoid operations that are excessively costly or wasteful. The display quantity is termed “Dynamic Fuel Cost” or DFC, usually measured and displayed in currency (such as Dollars or Euros) per hour. Once every second or so, up to six modes of vehicle operation are detected, including steady speed, acceleration, deceleration by coasting (reduced power or parasitic drag), regenerative braking (in vehicles so equipped such as hybrids), friction braking, and zero speed idling. Then DFC is computed and displayed to the operator. Operators can choose to operate the vehicle in ways that maximize the value of their time and minimize fuel consumption and resulting emissions of pollutants and greenhouse gases.