What happens as a result of tyre pressures being well below the recommended levels?

When tyre pressures are below the recommended levels, the tyre's contact with the road surface increases, leading to greater rolling resistance. This causes the engine to work harder, which increases fuel consumption. At the same time, the increased friction and deformation of the tyre result in faster and uneven tyre wear. Both factors not only affect safety and costs but also impact vehicle performance. Pollutant emissions generally increase, not decrease, due to higher fuel consumption, so choice 3 is incorrect. Maintaining proper tyre pressure is important for efficient driving and tyre longevity.