Maruun Transport — Japan
Nine Maruun Transport vehicles were compared October 2022 against October 2023. Six improved, by up to +26.0%. Three got worse — two loaders at −15.0% and −17.8%, and a 2 t box van at −2.2%. The median across all nine is +2.9%. This is the widest spread in our Japanese records and the one we would show first to anyone who suspects our data has been filtered.
A third of this fleet went the wrong way. That is not a footnote to the result — on a dataset this small it is half the information in it.
| Operator | Maruun Transport, Japan |
|---|---|
| Vehicles | 9 — 4 t flatbeds and wing bodies, a 2 t box van, and three loaders |
| Method | Same calendar month one year apart: October 2022 against October 2023 |
| Treatment | Applied in stages across 2022 and 2023 |
| Measured quantity | Fuel efficiency in km/L |
| Result | Median +2.9%, range −17.8% to +26.0% |
| Negative results | 3 of 9 vehicles |
| Emissions | Not recorded in this trial |
Every measurement, not just the best one
| Vehicle | ID | Oct 2022 (km/L) | Oct 2023 (km/L) | Distance 2022 → 2023 | Change |
|---|---|---|---|---|---|
| 4 t flatbed with gate | 千173 | 6.60 | 6.79 | 4,823 → 5,045 km | +2.9% |
| 4 t flatbed | 千181 | 6.34 | 6.51 | 4,515 → 4,454 km | +2.7% |
| 4 t wing | 千063 | 5.78 | 7.28 | 4,338 → 2,920 km | +26.0% |
| 4 t wing | 千159 / E24 | 5.31 | 6.57 | 2,812 → 3,140 km | +23.7% |
| 4 t wing | 千187 / E24 | 4.46 | 5.43 | 2,812 → 3,140 km | +21.7% |
| 1-unit loader | EC2100 | 4.70 | 4.98 | 1,212 → 3,082 km | +6.0% |
| 2 t box | E2200 | 7.73 | 7.56 | 2,684 → 2,086 km | −2.2% |
| 2-unit loader | C306 | 3.21 | 2.73 | 2,321 → 2,008 km | −15.0% |
| 2-unit loader | C313 | 3.42 | 2.81 | 2,088 → 2,463 km | −17.8% |
| Median across all 9 | +2.9% |
Method before result
Each vehicle was compared with itself in the same calendar month a year earlier. That structure removes most of the seasonal effect, which is why we rate it above a straight before-and-after comparison — the same reason the Alfresa and boiler datasets are among our better ones.
The treatment was applied in stages across the two years rather than on a single date, so the interval between application and measurement differs between vehicles and is not documented per vehicle.
The distance column matters more here than on most of our pages. Two vehicles did substantially different amounts of work in the two compared months — the 4 t wing 千063 drove 4,338 km in 2022 against 2,920 km in 2023, and the EC2100 loader went the other way, 1,212 km against 3,082 km. Where the workload changes that much, a km/L comparison is measuring the job as much as the engine.
One oddity we cannot explain: the two 4 t wing vehicles 千159 and 千187 are recorded with identical distances in both months (2,812 and 3,140 km). Identical figures for two different vehicles usually mean an estimate or a copied cell rather than two independent readings.
The limits of this trial
We publish these next to the result rather than in a footnote. If a limitation would change how you read the number, you should read it at the same time as the number.
Known limitations
- Three of nine vehicles consumed more fuel after treatment: the loaders C306 (−15.0%) and C313 (−17.8%), and the 2 t box van E2200 (−2.2%). Both loaders are the same vehicle type, which is worth noting rather than dismissing — it may point at a duty cycle where the treatment has less to work with, similar to the small and variable result recorded on the IHS Towers generators.
- Two vehicles show distance differences of 33% and 154% between the compared months. Their percentages should be read as unreliable rather than simply favourable.
- The identical distance figures recorded for 千159 and 千187 suggest at least one of them is not an independent measurement.
- There is no control group and the application dates are not documented per vehicle.
- We hold a summarised record of this trial, not the operator’s primary data. The method, the periods and the per-vehicle figures are documented; the underlying fuel and distance logs are not in our possession, and we have asked for them.
Reading this evidence in context
A median of +2.9% across nine mixed vehicles, with a third of them negative, is a modest and believable picture — and it is a more useful thing to show an operator than any single large number on this site.
The loaders are the interesting signal. Two vehicles of the same type both going the wrong way echoes the small, inconclusive result recorded at IHS Towers, on a different low-load duty cycle. We would want load and running-hours data before saying that is what happened here.
For a mixed fleet the practical reading is: expect a spread, expect some vehicles not to respond, and design the pilot so you can tell which is which.
Questions operators ask about this trial
Why publish a trial where a third of the fleet got worse?
What happened with the two loaders?
Is the median the number you stand behind?
Provenance
- Operator
- Maruun Transport, Japan
- Comparison
- October 2022 (baseline) against October 2023
- Source
- Japanese field-study summary — derived record
- Recalculation
- All percentages recomputed from the recorded km/L values
- Open items
- Primary fuel and distance records requested; per-vehicle application dates; load data for the two loaders
- Last checked
- 15 August 2026
The only baseline that matters is yours
Every trial on this site was run on someone else’s vehicles, duty cycle and baseline. A NanoEFX pilot measures yours — and we will help you design it with a control group so the result stands up.