A charged air duct for transferring compressed gas from a gas compression system eg turbocharger or supercharger to an inlet manifold of an internal combustion engine. The charged air duct comprises tubular outer member 200, a substantially tubular inner m...

An exhaust gas re-circulation system provides for intake of exhaust gases from a first end 206 into one of a plurality of corrugated inner tubes 204 housed within an outer tube 200. Corrugations in said inner tube 204 provide for an increased surface area ...