The study of inflation pressure for passenger car tyres represents a field of interest for automotive research, having major influence on tyre-road interaction, with respect to automotive dynamics and safety, vehicle comfort, rolling resistance, traction, braking and cornering. The investigation of inflation pressure is crucial in automotive testing, because essential information can be obtained concerning the behaviour of tyres in rolling conditions. The current paper focuses on experimental investigation of inflation pressure using measuring systems that can be mounted inside passenger car tyres. The aim of the paper is to perform the comparison of pressure transducers with measuring ranges adequate for study of inflation pressure but also with size and mass suitable to tyre mounting. For transducers validation, a newly designed testing rig has been developed to allow pressure adjustment and verification using digital and analog display manometers. Experiments have been performed for two small-size pressure transducers for determining the measuring range, sensitivity and offset. Conversion diagrams and linearity errors have been obtained experimentally for the two pressure transducers and very good repeatability has been ascertained. The sensitivity and offset provided by the transducers manufacturer were found to be different from real values obtained in laboratory tests, therefore the verification through experiments lead to update of these technical specifications. The experimental investigation of pressure transducers contributed substantially to the design of portable system for future application in tyre rolling conditions, but further research is required for development of pressure measuring system for road rolling tyres.