Patent ID: 8424630

Claim:
A method for controlling operation of an engine in a hydrostatically driven vehicle, the method comprising: monitoring an engine mode control input having at least a high mode setting and an economy mode setting; monitoring a propel control input associated with a propel pump operably coupled to the engine, the propel control input having a neutral position and a drive position; monitoring a propel pump sensor disposed to measure a displacement of the propel pump and generate a propel pump displacement signal, the displacement of the propel pump having a maximum displacement position; operating the engine in an economy mode when the engine mode control input is in the economy mode setting, the economy mode including: operating the engine at a fixed propel neutral speed when the propel control input is in the neutral position; operating the engine at a fixed propel drive speed when the propel control input is in the drive position and the propel pump displacement signal indicates the propel pump displacement is less than the maximum displacement position, the fixed propel drive speed being greater than the fixed propel neutral speed; and operating the engine at a variable drive speed when the propel control input is in the drive position and the propel pump displacement signal indicates the maximum displacement position.