Inflation pressure is no doubt the crucial parameter for tyre load capacity, ground pressure and the tyre’s service life. To get the pressure right you need a compressor and a tyre inflation pressure gauge, usually referred to as a tyre inflator or a tyre gauge. We checked out how accurately the gauge measure, whether factory-calibrated units make a difference and what to expect from inflators that use a digital gauge. Our test consisted of 15 candidates. The accuracy of the individual devices was verified by the Weights and Measures Office at Münster in Germany.