ONLY the 2.0-litre petrol C5 is available as a manual: turbo-diesel and V6 models come only with four-speed automatic gearboxes with sequential control. The four-cylinder gearboxes are produced by the PSA group (Peugeot, Citroen, Renault) while the V6 engine uses a higher capacity sequential four-speeder from ZF. In automatic mode, the gearbox computer reads parameters such as road surface, grip, vehicle loading, acceleration, deceleration as well as the selected programme (Sport or Snow) to decide which gears to select, and how long to hold them. Sequential mode is selected in standard fashion by moving the lever to the left.