Abstract: A transmission system comprises an engine (10) which drives a propeller shaft (14) through continuously variable gearing (CVG) (11), split path gearing (12), and a disconnector device (13). The gear ratio of the CVG (11) is controlled by an actuator (24). The input and output shaft speeds of the CVG (11) are sensed by transducers (25, 26) and the propeller shaft speed is sensed by a pair of transducers (27, 28). The system is responsive to an accelerator pedal (22) and a selector switch (23), and controls a throttle (19) via an electric motor (20).In normal operation, with the selector switch (23) in the drive position (D) or the reverse position (R), two signal generators (41, 42) calculate a target throttle position and a target engine speed and the motor (20) and actuator (24) adjust the throttle (19) and CVG (11) accordingly.When the switch (23) is in the neutral position (N) or the park position (P), the disconnector device (13) receives the drive from the propeller shaft (14). The speed (N.sub.

Abstract: A fuel control system for an internal combustion engine, including a fuel flow control sensitive to one or more engine operating parameters and controlling the rate at which fuel is introduced into the engine, an exhaust gas sensing device for producing an output signal corresponding to the exhaust gas composition, feed back means for feeding back to the fuel flow control, a signal derived from said output signal to correct the fuel flow, said feed back means including a signal storage device, the signal stored in which is altered in accordance with variations in the output signal of the exhaust gas sensing device, and overrun detection means connected to said feed back means and arranged to prevent alteration of said stored signal by the exhaust gas sensing device during overrun.