Runflat tyres and TIREFIT
Getting home safely with a flat tyre
does without a spare wheel well. This saves space and weight – the latter contributing to efficiency.
Tyres with run-flat capability are standard. These so-called MOE tyres (“Mercedes Original Extended”) feature the latest generation of run-flat technology, offering the same ride comfort as conventional tyres, despite reinforced sidewalls. In the event of a flat tyre, the journey can be continued at 80 km/h. The possible range is then around 30 kilometres when there is no air pressure whatsoever in the tyre concerned, or otherwise up to 300 km – sufficient to return safely home or to reach a Mercedes-Benz dealership.
The A 250 Sport does not have run-flat tyres and therefore come standard with the TIREFIT system comprising of tyre sealant and an electric pump.
All A-Class models feature the tyre pressure loss warning system as standard, which displays a warning in the instrument cluster in the event of a marked pressure loss. Input variables for the system are the speeds of the four wheels, which are recorded by the ABS sensors. A relative comparison of all measured wheel speeds reveals the divergent speed of a wheel in the event of a pressure loss in the tyre. As wheel speeds are also influenced by other dynamic variables, such as tyre slip, slip angle or cornering, the sensor signals from driving assistance systems such as ESP® and ADAPTIVE BRAKE (including ABS and ASR) also receive due consideration in assessing the wheel speeds.