A hydraulic system for a work vehicle having an engine, the hydraulic system comprising: a high pressure hydraulic circuit for providing high pressure hydraulic fluid to at least one of a hydraulic steering device, a hydraulic actuator, and a trailer brake valve; and a medium pressure hydraulic circuit for providing medium pressure hydraulic fluid to at least one of a hydrostatic or Continuously Variable transmission, a geared transmission, and a medium pressure hydraulic service; and a low pressure hydraulic circuit for providing low pressure hydraulic fluid to at least one vehicle lubrication circuit; characterized in that: the high pressure hydraulic circuit has a charge pump drawing hydraulic fluid from a reservoir, the charge pump providing pressurized hydraulic fluid only to a high pressure variable displacement pump, the high pressure variable displacement pump further pressurizing the hydraulic fluid and providing the further pressurized hydraulic fluid to a priority valve according to demand of the hydraulic steering device, hydraulic actuator, or trailer brake valve; and the medium pressure hydraulic circuit has a medium pressure variable displacement pump drawing hydraulic fluid from the reservoir and providing pressurized hydraulic fluid to the hydrostatic or CV transmission, geared transmission, or medium pressure hydraulic service according to demand of the hydrostatic or CV transmission, geared transmission, or medium pressure hydraulic service; and the low pressure hydraulic circuit has at least one low pressure variable displacement pump and no charge pump, the at least one low pressure variable displacement pump drawing hydraulic fluid from the reservoir and providing pressurized hydraulic fluid to the at least one vehicle lubrication circuit by way of at least one of a hydraulic oil cooler and a hydraulic oil cooler bypass, the hydraulic oil cooler and hydraulic oil cooler bypass being configured in parallel and being controlled by a proportional valve. a high pressure hydraulic circuit for providing high pressure hydraulic fluid to at least one of a hydraulic steering device, a hydraulic actuator, and a trailer brake valve; and a medium pressure hydraulic circuit for providing medium pressure hydraulic fluid to at least one of a hydrostatic or Continuously Variable transmission, a geared transmission, and a medium pressure hydraulic service; and a low pressure hydraulic circuit for providing low pressure hydraulic fluid to at least one vehicle lubrication circuit; characterized in that: the high pressure hydraulic circuit has a charge pump drawing hydraulic fluid from a reservoir, the charge pump providing pressurized hydraulic fluid only to a high pressure variable displacement pump, the high pressure variable displacement pump further pressurizing the hydraulic fluid and providing the further pressurized hydraulic fluid to a priority valve according to demand of the hydraulic steering device, hydraulic actuator, or trailer brake valve; and the medium pressure hydraulic circuit has a medium pressure variable displacement pump drawing hydraulic fluid from the reservoir and providing pressurized hydraulic fluid to the hydrostatic or CV transmission, geared transmission, or medium pressure hydraulic service according to demand of the hydrostatic or CV transmission, geared transmission, or medium pressure hydraulic service; and the high pressure hydraulic circuit has a charge pump drawing hydraulic fluid from a reservoir, the charge pump providing pressurized hydraulic fluid only to a high pressure variable displacement pump, the high pressure variable displacement pump further pressurizing the hydraulic fluid and providing the further pressurized hydraulic fluid to a priority valve according to demand of the hydraulic steering device, hydraulic actuator, or trailer brake valve; and the medium pressure hydraulic circuit has a medium pressure variable displacement pump drawing hydraulic fluid from the reservoir and providing pressurized hydraulic fluid to the hydrostatic or CV transmission, geared transmission, or medium pressure hydraulic service according to demand of the hydrostatic or CV transmission, geared transmission, or medium pressure hydraulic service; and the low pressure hydraulic circuit has at least one low pressure variable displacement pump and no charge pump, the at least one low pressure variable displacement pump drawing hydraulic fluid from the reservoir and providing pressurized hydraulic fluid to the at least one vehicle lubrication circuit by way of at least one of a hydraulic oil cooler and a hydraulic oil cooler bypass, the hydraulic oil cooler and hydraulic oil cooler bypass being configured in parallel and being controlled by a proportional valve.