1. Idle time – the silent cost driver
Analyses of machine telematics data show it time and again: on many construction sites, machines spend 20–40 % of their operating hours idling – waiting for trucks, during breaks, while repositioning. That costs three times over: diesel (several liters per hour), operating hours on the meter (resale value, service intervals) and, on newer machines, unnecessary regeneration cycles of the particulate filter. What works: automatic engine shutdown (auto idle stop), clear instructions to operators and a work rhythm that reduces waiting times. On most construction sites this is the single biggest lever.
2. Deployment planning & the right machine size
A 30-tonne excavator on a job a 20-tonner could handle burns unnecessary diesel every operating hour; a machine that is too small simply takes longer. Just as expensive: poorly planned earthmoving with long haul distances or double handling. Matching machine size, attachment and logistics to the task saves fuel without a single technical intervention – experience from construction process optimization puts the potential at 5–15 % of fuel use per trade, depending on the starting point.
3. Operator training & eco modes
Modern excavators and wheel loaders have power and eco modes – but they are far from always used. For most tasks, eco mode is sufficient with no noticeable loss of performance; full power mode belongs only in peak loads. Combined with trained working technique (digging depth, slew angle, travel paths), savings of 5–10 % are realistic – analogous to driver training on the road, and with the same caveat: without monitoring, the effect fades.
4. Maintenance & machine condition
Clogged air and fuel filters, worn cutting edges and teeth, wrong track tension on a tracked excavator or wrong tire pressure on a wheel loader – all of this increases fuel demand per cubic meter moved, typically by up to 10 %, before it ever shows up as a defect. On a construction site, with dust and constant load, filters and wear parts age much faster than on the road – service intervals should be adjusted accordingly.
5. Measuring consumption & comparing machines
Without figures, every measure remains guesswork. Most newer machines deliver consumption and idle share free of charge via the manufacturer's telematics; for older ones, the simple view of liters per operating hour from fueling data and the hour meter does the job. Only the comparison – between machines, operators and periods – reveals where the outliers are and whether a measure is working.
6. Fuel optimization with a retrofit system
Complementing workflows and maintenance, technical fuel optimization acts directly on combustion. The Fuel Eco Tech (FET) system is integrated into the fuel line – after the filter, before injection, with no intervention in the engine management – and therefore works on every operating hour, regardless of operator and construction-site hustle. Especially on machines with high annual operating hours and high sustained loads, this adds up.
As a real-world figure, there is a documented field test on a Unimog – a vehicle that, like many construction machines, is assessed by operating hours: in winter operation, around 10.9 % lower consumption per operating hour was measured against the reference period. In the standardized laboratory test (diesel), the figures averaged up to 6 % (WLTC) and up to 15 % at constant load. Test reports under News & laboratory test.
Context: the figures for idling, planning, training and maintenance are typical industry values from telematics analyses and construction process consulting; actual results depend heavily on the site and the machine fleet. The FET figures come from published tests.
Conclusion: idling first, then technology
If you tackle only one thing, start with idling – on most construction sites it is the biggest and cheapest lever. After that, the combination of operator training, adapted maintenance and an operator-independent technical building block such as fuel optimization pays off. Measurement happens in liters per operating hour – anything else is gut feeling.