The road transport sector, heavily reliant on oil-based fuels, significantly contributes to global greenhouse gas emissions. Improving vehicle aerodynamics is key to enhancing fuel efficiency, but crosswind disturbances increase drag and rolling resistance, especially for heavy-duty vehicles. This study examines the impact of extreme crosswinds on energy consumption and dynamic behaviour, focusing on driver steering responses at varying delay times. Simulations reveal that prompt steering mitigates energy losses, while delayed responses amplify rolling resistance and tyre slip angles. For instance, a 1-second delay increases energy consumption by 77%, compared to 44% for prompt steering.