Methodology and sources
How figures get on this site: sources, dating, rating logic.
Spec tiers: which source weighs heavier
A fixed ranking. In case of doubt the highest available tier shows; lower tiers only supplement and are labelled.
| Tier | Source | Use |
|---|---|---|
| 1 · register/official | RDW open data (NL), KBA (DE), comparable registers, type-approval data | Leading for homologation, recall and TSB signals |
| 2 · OEM datasheet | Official factory datasheets and technical brochures | Leading for version specs (power, WLTP, dimensions, payload) |
| 3 · curated reference | Recognised technical reference works, trade press with method | Only to confirm tier 1/2 or bridge a gap, labelled |
| 4 · owner sources | Owner forums, aggregated public owner figures | Never as a spec; only practice indications, with n |
An owner figure never overrides a register or factory specification. Where tier 1 and tier 2 differ (e.g. WLTP vs type-approval), the factory figure shows and the deviation is named, not averaged.
Rating categories: source and weighting
Six categories. Per model the source used and the reference date are visible at each category; that field is mandatory in our data. A category gets a figure only with enough traceable data points; otherwise the score stays empty and the page shows "insufficient data".
| Category | Based on | Weighting |
|---|---|---|
| Sustainability | WLTP consumption/emission, battery and drivetrain warranty, public LCA indications (e.g. ICCT) | Factory figure weighs heaviest; LCA only with an independent source, otherwise not weighed |
| Reliability | ADAC Pannenstatistik (segment/model where available), recall and TSB data (RDW/KBA), aggregated owner signals | Register and breakdown data lead; owner signals confirm direction, never sole basis |
| Efficiency | WLTP as reference | Relative within segment/drivetrain; no euros, no cost price |
| Combined consumption | WLTP combined plus owner real-world (shown separately) | WLTP and real-world side by side, never merged; real-world only with sufficient n |
| Practicality | Dimensions, boot, payload, towing weight from OEM datasheet/register | Published measurements only; no subjective driving feel |
| Value retention | Residual-value indications from public, methodically described sources | Only with sufficient reliable points; with thin data no figure |
Why sometimes "insufficient data"
An empty figure is a choice, not an omission. With too few traceable points, a source too broad, or unresolvable conflicting sources, we show "insufficient data" explicitly. No interpolating, no estimating, no borrowing from another model. A non-traceable score is misleading; an honest gap is not.
Reference-date discipline
Specs, prices, ratings and tax references carry a reference date. If the underlying source changes (new model-year datasheet, new statistics, price change), the reference date moves at the next revision. No old value presented as current. Tax references are always indicative and tied to the stated reference date, not to "now".
Prices and price history
Prices are indicative "from" prices with a reference date, not a quote and not a current daily price. Currently-orderable models show a from-new price; discontinued models show no new price, at most a historical introduction price as context. The price history (/auto/…/prijzen/) is a series of recorded from-prices each with its own date, maintained manually from official price lists. No quote feed, no "model A is cheaper than B" conclusion.
Real-world consumption (realVerbruik)
Besides WLTP, some models show owner-reported real-world consumption. A separate value with unit, source, sample size (n) and reference date, shown next to the factory figure, not in its place. With sample too small or non-traceable, no real-world figure. We do not measure ourselves; we label the origin.
Reviews as input
Summaries of external sources are labelled, summarised transformatively and linked to source. Owner reviews come in anonymously, are moderated before publication and smoothed only on spelling and readability, never sentiment or figure. An individual review is never on its own a rating source; only aggregated, traceable signals weigh in. See the review policy and the transparency page.
Correction process (art. 6:194 BW)
Misleading or incorrect product information is a real liability risk; traceability is our structural mitigation. Think a spec, price or score is wrong? Report it with a source through the correction form or the contact address. We test the report against the highest available source tier. Safety-critical fields (towing weight, payload, braking distance, recall status) get priority and a visible reference-date adjustment where relevant. If the report does not hold against a higher source, the value stays and we explain on request.
No tax or financial advice. Every figure shows its source and reference date. Always compare with an independent adviser and the official source.