<p>A tyre inflation control system for a tractor (10) has an inflation means (13) for inflating and deflating tyres (11, 12) of the tractor. Conduits (14,15) connect the inflation means (13) with the tyres, and a control means (20) connected with the inflation means is provided for storing predetermined tyre pressure levels and initiating the changing of the inflation pressure of the tyres between the predetermined pressure levels set in the control means. The predetermined tyre pressure levels can conveniently correspond to a field work pressure level and a road work pressure level and the control means can store inflation pressures for the tyres of both the tractor (10) and any associated trailer (16) or machine being towed by the tractor. The control means may include an electronic display monitor (20a) with a touch sensitive screen through which the predetermined levels of tyre pressure can be entered.</p>
