John Deere X590 Tractor with 48" or 54" Deck

The constant-speed governor works together with electronic fuel injection (EFI) to keep the engine of the X590 operating at an optimum speed, responding instantaneously as the mower transitions from light to heavy mowing. 

When the load increases, the engine speed on the X590 remains constant, thus cutting mowing time and grass down to size. This may well be a first for lawn tractors everywhere.