Under inflated tyres increase your vehicle’s drag, which increases fuel consumption. But by how much exactly? Under inflation of the tyre by 10 per cent increases fuel consumption by 2 per cent. Twenty per cent under inflation increases fuel consumption by 4 per cent. With tyre pressure at 40 per cent below the recommended level, the tyre’s fuel consumption increases by 8 per cent.

This can have a significant effect over time as tyres can naturally lose one to two PSI per month. Changes in temperatures can also affect tyre pressure. For every 5 °C drop in temperature, there is a 2 per cent loss in tyre pressure. Your tyre also inflates about 2 per cent with a 5 °C rise in temperature. If the temperature fluctuates throughout the year or even from day to night, the effect can be significant.