Dalton's theory was identified using light microscope images of atoms.
Because the air inside the tires is kept at high pressure.
In fact, the force applied by the tires upwards to counter-balance the weight of the car (pushing downwards) is
where p is the pressure of the air inside the tires and A is the area of contact between the tire and the car. Therefore, a higher pressure means a larger force F, and eventually if the pressure p is higher enough the force F will be large enough to counterbalance the weight of the car.