A central tire inflation system for a tire. The system includes one or more pneumatic control valves for controlling inflation of a respective tire. A first compressed air source is provided for supplying compressed air to inflate the tire. A second compressed air source is provided for supplying compressed air to control the at one or more pneumatic control valves. A control means is provided for controlling the supply of compressed air from the second compressed air source to generate a pneumatic control signal to control the one or more pneumatic control valves. The first compressed air source can be a compressor configured to provide compressed air to inflate the tires. The second compressed air source can form part of an air suspension system.