The objective and novelty of this work is the development of a physical modular tire that enables the aerodynamic investigation of tire geometrical parameters in a controlled and isolated way. This ongoing study includes wind tunnel measurements of multiple market-available 245/45 R18 tires, as well as future ones from the modular tire (size 245/45 R18). All the tests are carried out on the BMW 4 series electric (G26 generation) at the BMW wind tunnel facilities. The potential impact of the gained knowledge through this work is substantial, given that tires account for 10-15% of the total car drag (Simulation results of the G26). This influence has been observed in the until-now conducted wind tunnel measurements of current market-available 245/45 18 tires, with max ΔCx = 0, 009. In other vehicle and tire shapes this value is known to be up to max ΔCx = 0, 015, which is equivalent to ≈ 20 km of range (factor ranges between 1,1 and 1,5). The shape variability of the currently tested tires only represents a subset of the design space in which tire manufacturers develop their geometries. Hence, a modular tire is under development to fully explore the design space isolating geometrical parameters during the study.