Method of operating a vehicle and a vehicle

A method of operating a vehicle,

• the vehicle comprising:
• an engine;
• a throttle operator being moveable by a driver of the vehicle;
• a throttle valve regulating airflow to the engine, a throttle valve position being based at least in part on a throttle operator position;
• a continuously variable transmission (CVT) operatively connected to the engine, the CVT including a driving pulley, a driven pulley, and a belt operatively connecting the driving pulley to the driven pulley;
• at least one ground engaging member operatively connected to the driven pulley and comprising at least one of:
• a wheel and a track;
• a piston operatively connected to the driving pulley for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley;
• and
• a control unit for controlling actuation of the piston and the piston force,
• the method comprising:
• determining an engine speed;
• determining at least one of the throttle operator position and the throttle valve position;
• detecting a negative load condition indicative of a negative load on the engine, the negative load condition comprising:
• the engine speed being greater than a downhill threshold engine speed;
• and
• at least one of:
• the throttle operator position being lower than a downhill threshold throttle operator position;
• and
• the throttle valve position being lower than a downhill threshold throttle valve position;
• and
• responsive to the detection of the negative load condition, controlling the piston force based on the engine speed.