Why is the total stopping distance of a fully loaded 45-tonne commercial combination significantly longer than that of a standard passenger car?

1. Heavy trucks use smaller tires than passenger cars
2. Tremendous kinetic energy from 45 tonnes of mass requires substantial friction dissipation, and pneumatic brake application has an inherent lag time (retardo neumático of 0.3 to 0.6 seconds)
3. Truck drivers always have slower reaction times
4. Diesel engines generate negative braking vacuum