Rolling Resistance
Rolling resistance is the force that opposes a vehicle’s motion because tyres and other rolling components deform and dissipate energy as the vehicle moves.
What changes the resistance
Tyre construction, compound, pressure, temperature, load, wheel alignment, bearing losses, and road surface all matter. A common simplified model treats rolling-resistance force as a coefficient multiplied by the normal load, but the coefficient is not perfectly constant: it can change with speed, temperature, pressure, and operating condition.
Rolling resistance is distinct from aerodynamic drag. Its force is often approximated as roughly proportional to vehicle weight over a limited range, while aerodynamic force rises with the square of air speed. Rolling resistance can therefore be a large share of road load at lower speeds, whereas aerodynamics usually becomes more dominant at sustained high speed.
Low-rolling-resistance tyres can reduce energy use, but tyre choice also involves grip, braking, comfort, noise, wear, load capacity, and winter performance. Incorrect pressure can increase resistance and impair other tyre characteristics. The vehicle manufacturer’s specified pressures and compatible tyre ratings remain the practical reference.
For the complete road-load and range model, see Understanding EV Range.