Propagation models used to plan outdoor wireless networks on urban environment, tend to include a high degree of empirical component. These are derived from the difficulties of accurately estimate the influence of obstacles, buildings and terrain in the signal path loss. Therefore, the final equation usually contains constants, and coefficients for the different terms, mainly obtained by statistical analysis of measurement sets, collected during drive tests on large areas of the city. Unfortunately, such results are only truly valid for the city or parts of the city on which the measurements were taken. They can also be considered appropriate for similar areas or cities at the most. If the areas are not similar enough however, a process of adjustment is necessary, leading to the finding of new constants and coefficients. The purpose of this paper is to discuss some of the findings during the process of statistically adjust the Okumura-Hata and Walfisch-Bertoni models to the Cali scenario, using measurements.