Why Methodology Matters
The electric vehicle industry generates an enormous volume of data — sales figures, technical specifications, financial disclosures, production estimates, and charging infrastructure statistics — from sources that span multiple languages, regulatory regimes, and reporting standards. Without a clear, consistent methodology for collecting and interpreting this data, comparisons become meaningless and conclusions become unreliable.
This page documents exactly how we gather, verify, convert, and present the data that appears across all EVSays content. If you use our numbers in your own reporting, research, or investment decisions, this is your reference for what those numbers mean and where they came from.
Data Collection & Primary Sources
EVSays collects data from the following categories of sources, prioritized by proximity to the original event or disclosure:
Tier 1 — Regulatory & Official Disclosures
- MIIT filings (Ministry of Industry and Information Technology, China): New vehicle homologation filings, including dimensions, powertrain specifications, battery chemistry, and curb weight. These are legally binding filings required before any vehicle can be sold in China.
- CPCA reports (China Passenger Car Association): Monthly wholesale and retail sales data for the Chinese market. CPCA data is the industry standard for China auto sales tracking.
- Company financial filings: Quarterly and annual reports filed with stock exchanges (Shanghai, Shenzhen, Hong Kong, New York) containing audited sales volumes, revenue, gross margins, and production capacity.
- Government agency announcements: Tariff determinations, subsidy policy changes, and trade regulations issued by agencies including China’s NDRC, the EU Commission, U.S. Department of Commerce, and equivalent bodies.
Tier 2 — Corporate Disclosures
- Official press releases: Published through corporate websites, WeChat official accounts, Weibo, and global PR newswires.
- Investor presentations and earnings calls: Transcripts and slide decks from quarterly briefings.
- Executive statements: Comments made during media interviews, industry conferences, and social media posts from verified corporate accounts.
Tier 3 — Industry & Media Reports
- Established automotive media: Including Nikkei, Reuters, Bloomberg, Automotive News, CarNewsChina, CnEVPost, LatePost (晚点), and Gasgoo (盖世汽车).
- Industry analysts: Reports from GF Securities, CITIC Securities, SNE Research, Rho Motion, and other firms with verified track records in the EV sector.
- Supply chain intelligence: Battery material pricing, cell production capacity, and semiconductor allocation data from industry tracking services.
When a single-source claim cannot be independently verified, we flag it explicitly with qualifying language such as “according to” or “the company claims.” Our full sourcing standards are detailed in our Editorial Policy.
Currency Conversion Standards
All prices originally denominated in Chinese yuan (CNY/RMB) are converted to U.S. dollars (USD) using the exchange rate in effect at the time of publication. Our conversion methodology:
- Exchange rate source: We use the People’s Bank of China (PBOC) daily central parity rate or the prevailing mid-market rate at time of writing, noted in each article where conversions appear.
- Rounding: Vehicle prices are rounded to the nearest $100. Component and per-unit costs are presented to the nearest dollar or cent as appropriate to the context.
- Context: Where relevant, we note that Chinese-market prices do not include international shipping, import duties, or destination charges, and should not be directly compared to final consumer prices in export markets.
- Dual display: All converted figures are accompanied by either the original CNY figure or a parenthetical note confirming the conversion basis.
Sales & Market Data Methodology
China Market Sales Data
Monthly sales figures for the Chinese market are drawn from CPCA wholesale data unless otherwise noted. Wholesale figures represent vehicles shipped from factories to dealerships — not end-consumer registrations. When retail (registration) data is available from CPCA or insurance registration databases, we specify which metric is being used.
Global Sales Comparisons
Cross-market sales comparisons require careful normalization. We adjust for:
- Reporting period differences: Some automakers report calendar-month sales; others report on fiscal calendars. We note any misalignment.
- Vehicle classification differences: What qualifies as an “SUV” or “NEV” varies between China, Europe, and North America. We use the classification standard of the reporting market and note discrepancies.
- Wholesale vs. retail: We specify which metric is used and do not mix them within a single comparison.
Penetration Rate Calculations
New Energy Vehicle (NEV) penetration rates are calculated as NEV sales divided by total passenger vehicle sales within the specified market and time period. “NEV” follows the Chinese definition — battery electric vehicles (BEV) plus plug-in hybrid vehicles (PHEV) — unless otherwise noted. Markets outside China may use different definitions; we specify the definition used in each case.
Technical Specification Verification
Vehicle specifications — including battery capacity, range figures, charging speeds, motor output, and dimensions — are verified through the following hierarchy:
- MIIT homologation filings: The definitive source for Chinese-market vehicle specifications. These are legal filings and carry the highest evidentiary weight.
- Manufacturer official specifications: Published spec sheets and technical documentation from automakers.
- Third-party testing: Independent range tests (e.g., WLTP, EPA, CLTC results), charging curve measurements, and instrumented performance testing from recognized test organizations.
- Media reports: When a specification is only available through media reports without official confirmation, we qualify it explicitly.
Range figures disclosure: Every range figure published on EVSays is accompanied by the testing standard under which it was measured — CLTC (China), WLTP (Europe), EPA (United States), or NEDC (legacy). Readers should understand that CLTC figures are typically 15–25% higher than EPA figures for the same vehicle due to differences in test cycle design. We do not mix testing standards within a single comparison without explicit conversion notes.
Review & Product Testing Standards
When EVSays publishes vehicle reviews, test drives, or hands-on evaluations:
- Disclosure: We disclose whether the test vehicle was provided by the manufacturer, rented independently, or accessed through a media fleet program.
- Test conditions: Route type, weather conditions, ambient temperature, and driving mode settings are documented where they materially affect performance data.
- No guaranteed coverage: Manufacturer-provided vehicles are accepted for evaluation purposes only. Acceptance does not guarantee coverage, nor does it influence the conclusions of any review. Our full conflicts-of-interest policy is available in the Editorial Policy.
Image & Multimedia Attribution
All images, videos, charts, and data visualizations published on EVSays are sourced and attributed as follows:
- Official manufacturer imagery: Used under fair use / editorial purposes, with source attribution.
- Third-party photography: Licensed or used with permission; photographer and source credited.
- Original EVSays content: Charts, data visualizations, and original photography produced by our team are marked as such.
- AI-generated imagery: EVSays does not publish AI-generated images representing real vehicles or events.
Data Update & Refresh Policy
Evergreen content — including guides, explainers, and comparison pages — is reviewed and updated on the following schedule:
- Monthly: Sales trackers, market share data, and pricing comparison tables.
- Quarterly: Company profiles, model lineup overviews, and technology explainers.
- Event-driven: Any page referencing a specific model or technology is updated when a new generation, facelift, or major specification change is announced.
When a substantive update is made to a page, we update the “Last updated” date and, where the changes materially alter the article’s conclusions, add an Editor’s Note summarizing the revision. Our full approach to content revisions is documented in the Correction Policy.
Limitations & Caveats
We believe in transparency about what our data can and cannot tell you:
- Chinese-market data: MIIT filings and CPCA reports are considered reliable, but reporting lags, reclassifications, and retroactive adjustments do occur. We note these when we become aware of them.
- Self-reported data: Sales figures released by automakers — particularly for export markets — are sometimes unaudited and may include channel-stuffing or strategic timing adjustments. We flag unaudited figures as such.
- Speculative content: Articles covering unannounced products, supply chain rumors, or analyst projections are clearly labeled as analysis or speculation and are separated from our news reporting.
- Forward-looking estimates: Any projection of future sales, market share, or technology timelines includes the basis for the estimate and an acknowledgement of uncertainty.
Related Policies
- Editorial Policy — Our sourcing standards, AI policy, fact-checking process, and conflict-of-interest rules.
- Correction Policy — How we handle errors, from minor typos to substantive retractions.
- About EVSays — Our mission, team, and editorial independence commitment.
- Contact Us — For methodology questions, data inquiries, or to report an error.
