The implementation of an advanced process for the aerodynamic development of cab-over type heavy trucks at FAW requires a rigorous validation of the tools employed in this process. The final objective of the aerodynamic optimization of a heavy truck is the reduction of the fuel consumption. The aerodynamic drag of a heavy truck contributes up to 50% to the overall resistance and thus fuel consumption. An accurate prediction of the aerodynamic drag under real world driving conditions is therefore very important. The tools used for the aerodynamic development of heavy trucks are wind tunnels and CFD. Wind tunnels have a number of limitations which make it difficult to predict on road performance of the truck. Such limitations are limited availability, blockage and pressure gradient effects, lack of road simulation and Reynolds number effects. While on the other hand CFD does not have such limitations the accuracy of CFD is often questioned and needs to be proven. In this study an extensive test program for a FAW heavy truck has been carried out in the NRC wind tunnel. For a direct comparison of forces and pressures between wind tunnel and CFD, a model of the wind tunnel is included in the CFD simulations and a blockage correction method consistent with the NRC wind tunnel correction is applied to the CFD results. CFD is also used to predict the drag under open road driving conditions and results are compared to the blockage corrected data from wind tunnel test and simulation. For validation measures and simulated results for wind averaged drag are then entered into a fuel consumption model to predict the fuel consumption for open road cruising at 90 km/h which is compared to respective test track measurements. I would like for this written paper to be considered for a presentation at COMVEC 17.