The calculation of the fuel consumption, fuel economy and carbon dioxide emissions (CO 2) of a heavy-duty vehicle is detailed. First the forces over a vehicle in motion are calculated and then the necessary torque and the revolutions per minute (rpm) of the engine to provide the tractive force are found. The fuel consumption in kilograms per second for a pair of rpm and torque is obtained from the engine fuel map. The CO 2 emissions are obtained from the fuel consumption. The maxima of the torque and power of a 455 horse power engine are presented as a function of the rpm as well as the specific fuel consumption of the vehicle at the maxima values of the torque. Finally, the fuel economy of the vehicle moving in part of one of the cycles used by the Environmental Protection Agency of the United States of America to certify heavy-duty vehicles to fuel consumption and CO 2 emissions is calculated.

The fuel economy and carbon dioxide emissions (CO 2) of a heavy duty pickup moving in a driving cycle is calculated using the sofware UAMmero. The driving cycle consists of three parts: in the first part the vehicle is simulated to travel in an urban region in which the speed changes constantly, in the second part the simulated vehicle travels in a highway with a cruise speed of 88.514 kilometers/hour and in the third part the simulated vehicle travels at a cruise speed of 104.607 kilometers per hour. Results for the fuel economy and CO 2 emissions for a 4.407 ton, six gear transmission, 200 horse power diesel engine heavy Duty pickup are presented for different masses of the loads and slopes of the road. These results are part of a study to propose a method to certify heavy duty vehicles for fuel economy and CO 2 emissions in Mexico.