ALSOK (Kanagawa) — Japan
14 security transport vehicles operated by ALSOK in Kanagawa were measured in two different ways, and the two ways do not agree. The 11 vehicles compared against the same period a year earlier give a median of +8.8%, spread from +4.3% to +20.2%. The 3 measured directly before and after treatment give +50.3%, +30.2%, +21.6% — every one of them above the highest year-on-year result. Read the method column before the result column.
One operator, one fleet, two measurement methods — and a gap between them that is larger than the effect either method is trying to measure.
| Operator | ALSOK — recorded as 警送神奈川 (Kanagawa security transport) and 川崎支社 (Kawasaki branch) |
|---|---|
| Vehicles | 14 — Nissan Caravan, Isuzu Elf, Isuzu Como, Succeed |
| Fuel | Petrol (12 vehicles), diesel (1) |
| Method A | 前年比較 — comparison with the same period a year earlier (11 vehicles) |
| Method B | 施工前後比較 — direct before-and-after comparison (3 vehicles) |
| Result, method A | Median +8.8%, range +4.3% to +20.2% |
| Result, method B | +50.3%, +30.2%, +21.6% |
| Measurement period | Not recorded in the dataset |
Every measurement, not just the best one
| Vehicle | Fuel | Before | After | Change |
|---|---|---|---|---|
| Nissan Caravan (1) | Gasoline | 6.35 | 7.63 | +20.2% |
| Nissan Caravan (2) | Gasoline | 6.83 | 7.65 | +12.0% |
| Nissan Caravan (3) | Gasoline | 7.01 | 7.31 | +4.3% |
| Nissan Caravan (4) | Gasoline | 7.05 | 7.49 | +6.2% |
| Nissan Caravan (5) | Gasoline | 6.76 | 7.13 | +5.5% |
| Nissan Caravan (6) | Gasoline | 6.78 | 7.38 | +8.8% |
| Nissan Caravan (7) | Gasoline | 6.07 | 7.04 | +16.0% |
| Nissan Caravan (8) | Gasoline | 6.58 | 7.29 | +10.8% |
| Nissan Caravan (9) | Gasoline | 6.53 | 6.98 | +6.9% |
| Nissan Caravan (10) | Gasoline | 6.72 | 7.58 | +12.8% |
| Nissan Caravan (11) | Gasoline | 7.34 | 7.70 | +4.9% |
| Isuzu Elf | Diesel | 5.27 | 7.92 | +50.3% |
| Isuzu Como | Gasoline | 4.94 | 6.43 | +30.2% |
| Succeed · Kawasaki branch | Gasoline | 6.95 | 8.45 | +21.6% |
| Median across all 14 measurements | +11.4% |
Method before result
The 11 Nissan Caravan vans were compared against the same operating period a year earlier — the method the dataset records as 前年比較. Comparing like calendar periods removes most of the seasonal variation that makes a straight before-and-after fuel comparison hard to read, which makes these the more trustworthy figures of the two groups.
The remaining 3 vehicles — an Isuzu Elf, an Isuzu Como and a Succeed at the Kawasaki branch — were recorded as 施工前後比較, a direct before-and-after comparison with no seasonal control at all. Those three produced +50.3%, +30.2%, +21.6%.
That split is the finding worth taking away from this operator. Every single before-and-after measurement lands above the highest of the eleven year-on-year measurements (+20.2%). The vehicles are from the same fleet and the same operator; what changes is how the comparison was drawn.
Every percentage on this page was recalculated by us from the recorded before-and-after figures rather than taken from the summary column of the source; all of them reproduce the recorded value. That is a check on transcription, not on the measurement itself — it confirms the arithmetic is right, not that the reading was.
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
- The 3 before-and-after measurements have no seasonal or operational control whatsoever. We publish them because they are in the dataset, but we do not treat +50.3% on a single Isuzu Elf as a result.
- The two branches are recorded separately in the source (警送神奈川 and 川崎支社) and are combined on this page as one operator. If they should be read as separate fleets, the Kawasaki figure is a single vehicle.
- What "the same period a year earlier" covers is not documented — neither the months, nor the distance driven, nor whether the routes were unchanged.
- A separate ALSOK Vietnam record (2 vehicles, Ho Chi Minh City) sits in a different, undocumented part of the dataset. It is deliberately not merged into these figures.
- This is a dataset entry, not a trial report. What we hold is the before-and-after fuel-efficiency figure per vehicle as recorded in the master test dataset — not the operator’s raw fuel logs, not the odometer readings behind them, and not a written test protocol.
- There is no control group. No comparable untreated vehicle was tracked over the same period, so seasonal, route and traffic effects cannot be separated from the treatment.
- The measurement dates and the length of each measurement period are not recorded in these entries. We therefore cannot say how far each vehicle ran between the two readings, or which months the comparison covers.
- The figures were recorded by the operator or by the local distributor, not by an independent party, and we cannot re-derive them from primary records.
Reading this evidence in context
For an operator, this is the most useful page in the section, because it is a controlled illustration of an uncontrolled problem: the same product on the same fleet produces a median of +8.8% or a set of results up to +50.3% depending only on how the comparison is drawn.
Our reading is that the +8.8% median is the number to plan with and the before-and-after figures are the number to distrust — including, and especially, when they favour us.
It is also why we design pilots around a control group rather than a before-and-after snapshot. The methodology page sets out what that looks like in practice.
Questions operators ask about this trial
Which of the two figures should we believe?
Why publish the +50.3% figure at all if you do not stand behind it?
Was the driver aware of the treatment?
Does this dataset support a fleet-wide figure for security transport?
Provenance
- Source
- Eco-Spray / NanoEFX master test dataset, compiled 22 March 2020 — operator-named section
- Recalculation
- All percentages recomputed from the recorded before-and-after figures
- Raw records
- Held by the operator or the local distributor — not in our possession
- Operator entries
- 警送神奈川 (13 vehicles) and 川崎支社 (1 vehicle)
- Method as recorded
- 前年比較 (year-on-year) and 施工前後比較 (before/after)
- Name release
- Operator naming approved by ECO EFX Solutions, 15 August 2026
- 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.