This paper focuses on determining routes for logistics service providers from distribution centers to customers with the objective of minimizing the total costs. Despite being a particular example of the vehicle routing problem (VRP), this issue is more complicated than the basic VRP, especially since each vehicle contains heterogeneous capacity. This paper presents the novel strategy of Differential Evolution (NSDE) to solve multi-fleet size and Vehicle Routing Problems in logistics service providers (MFSVRP-LSP). Our work aims to minimize distance. The validation of NSDE (i.e., DE, NSDE1, NSDE2, NSDE3, NSDE4) was conducted by the comparison of the current practice. The relative improvement (RI) between the standard DE and the NSDE1, NSDE2, NSDE3, and NSDE4 in the MFSVRP-LSP. The NSDE4 outperformed the standard DE follow by my report. Furthermore, our suggested technique can be used for similar logistics in Thailand.