Vehicle lateral dynamics and state estimations highly depend on tire characteristics. Numerous tire models were developed to describe the tire behaviors. Among them, the empirical tire models, generally obtained through lab tests, are commonly used in vehicle dynamics and control analysis. However, the empirical models often do not reflect the actual dynamic interactions between tire and vehicle under real operational environments, especially at low vehicle speeds. This paper proposes a dynamic-deflection tire model to address the tire-vehicle interactions. This tire model can be incorporated with any conventional vehicle model to accurately predict the resonant mode in the vehicle yaw motion as well as the steering lag behavior at low speeds. A snowblower was tested as an example and the data gathered verified the predictions from the improved vehicle lateral model.