A power delivery system for a vehicle is disclosed. In one embodiment, the power delivery system includes a chassis engine configured to power driving functions of the vehicle and an auxiliary engine configured to power non-driving hydraulic functions of the vehicle. The power delivery system may also include a power boost system comprising a hydraulic pump and a hydraulic motor in fluid communication with each other. The hydraulic pump may be coupled to a power output of the chassis engine while the hydraulic motor may be coupled to a power output of the auxiliary engine. In one embodiment, the power delivery system has a power sharing mode in which power is transferred from the chassis engine power output to the auxiliary engine power output via the hydraulic pump and motor such that the non-driving hydraulic functions of the vehicle are simultaneously powered by the chassis engine and the auxiliary engine.