Regulations like TIER IV Final and STAGE IIIb compel mobile construction machinery manufacturers to minimize exhaust elements, a challenge that cannot be met solely through engine modifications. Consequently, engines with reduced power become a viable compromise, necessitating enhanced overall hydraulic efficiency to perform the same tasks. Rising fuel costs due to dwindling energy resources further pressure customers for increased productivity without altering machine handling characteristics. This context motivates the exploration of strategies to help developers navigate these conflicting demands. The thesis focuses on improving efficiency in mobile hydraulic systems, presenting a methodology for evaluating various system designs, even with limited cycle data. While results are not universally applicable, cycle-based data can reflect machine usage and identify potential power reserves in new hydraulic designs. The study centers on hydraulic system simulations, using a crawler excavator as a representative example of conventional work hydraulic systems, which includes typical subsystems in mobile hydraulics. Key attention is given to the interaction between the engine and work hydraulics. The methodology is applied to a load-sensing system, comparing fifteen new designs, including three based on a throttle-free principle. Results are depicted through plot diagrams showing cumulative energy across operation points in each com
