Nowadays, the new emission regulations and customer requirements such as low level of fuel consumption, mass reduction, NVH (noise, vibration and harshness) are pushing the product development to the limit. Thus, engine balancing become a vital aspect during the ICE (internal combustion engine) development cycle.The crankshaft balancing plays an important role in the engine vibration. As a consequence, the balancing criterion may be correctly applied in order to improve the engine performance.This work shows an inline-four cylinder crankshaft static balanced and its performance under virtual engine operation. Not only is the crankshaft balancing discussed, but also dynamic performance.Moreover, in order to have a lightweight crankshaft, a sensitivity study was performed to understand the influence of counterweights reduction. Thus, it was showed that if an alternative design is desired, there are some alternatives to minimize the unbalancing impact when saving counterweight mass.