Tire Cost of Ownership Relative to Vehicle Energy Cost, Route, and Tread Depth 2021-01-0938

Use of passenger and light truck vehicle fleets is likely to increase. Reducing operating cost is a common objective of fleet owners. Tires impact cost in two primary ways, rolling resistance and replacement cost. The total cost due to rolling resistance, replacement cost, and other secondary contributions is referred to as ‘tire total cost of ownership’. Both costs due to rolling resistance and replacement are a function of the driving route and the tread depth. In this paper, tire total cost of ownership for a broad distribution of routes is compared in a relative sense to the other route-dependent energy consumption costs resulting from vehicle inertia and vehicle aerodynamic drag. The algorithm developed includes the route history of velocity and forces on the tires and their effect on tire rolling resistance, tire wear rate, energy required to accelerate the vehicle inertia, and the energy lost to aerodynamic drag. The algorithm includes many inputs such as replacement price of tires, price of gasoline/electricity, gasoline/electric-grid to wheel efficiency, regenerative braking efficiency, aerodynamic drag coefficient, vehicle mass, tire rolling resistance, tire wear energy vs. forces, and tread rubber abradability. Tire cost of ownership was found to be 19-43% of the vehicle energy cost plus tire replacement cost depending on route and vehicle. Therefore, there is incentive to minimize the tire total cost of ownership. New tire tread depth is used as the variable in the cost minimization. A different minimum new tire tread depth exists for each combination of route and other algorithm inputs. There can be significant cost of ownership increases if the tread depth is reduced too much in pursuit of low rolling resistance due to the accompanying lower wear life.