Load-sensing hydraulics are sold on fuel savings. Our open heavy-hydraulics programme has been asking how true that is for a small excavator, and today's step puts prices on it.
Earlier steps showed the energy saving depends mostly on one number we could not source: the pressure an open-centre valve block holds with the levers neutral. At 8 bar load-sensing saves almost nothing; at 20 bar about 0.4 kW on average; at 40 bar about 1.1 kW. Against retail prices (a 28 cc load-sensing piston pump at $1,708 versus a 28 cc gear pump at about $147, plus a valve we could not price because makers quote on request) and diesel at about $6.28 a gallon, the extra parts repay in 2,566 hours at the very best and typically 7,000 to 14,000 hours or never. Our hypothesis of repayment within 2,000 hours is refuted across the whole grid.
The caveats matter: the parts are different brands, fuel use is an assumed typical figure, the duty cycle comes from another machine, and a piston pump gives you things fuel does not price. Numbers and code are in research/heavy-hydraulics.