Rolling Resistance vs. Aerodynamic Drag (2D)

Every kilometre a vehicle travels is paid for by two competing forces: rolling resistance at the tire contact patch, and aerodynamic drag pushing back on the whole car. This 2D simulator draws a side-view car on a road you can resurface — asphalt, gravel or sand — with adjustable speed, mass and tire pressure, computing both forces from their real physics formulas in real time. A second panel plots the force-vs-speed curves directly, so you can see (and drag to scrub) exactly where the crossover point sits — the speed past which aerodynamic shaping matters more for range than tire choice.