Data Methodology

How we gather, verify, convert and present the data across all EVsays content.

Why Methodology Matters

The electrification 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 for the Chinese market, including dimensions, powertrain specifications, battery chemistry and curb weight.
• CPCA reports (China Passenger Car Association): Monthly wholesale and retail sales data for the Chinese market.
• 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 the relevant national and regional bodies.
• Battery & energy-storage data: Cell and pack supply figures from SNE Research, Rho Motion and comparable industry trackers.

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 media: Including Nikkei, Reuters, Bloomberg, Automotive News, CarNewsChina, CnEVPost, LatePost and Gasgoo.
• Industry analysts: Reports from GF Securities, CITIC Securities, SNE Research, Rho Motion and other firms with verified track records.
• 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

• Exchange rate source: 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.
• Context: 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 data is available, we specify which metric is being used.

Global sales comparisons: Cross-market comparisons require careful normalization. We adjust for reporting-period differences, vehicle-classification differences and wholesale-vs-retail definitions, and we specify which metric is used in each case.

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 period. “NEV” follows the Chinese definition — battery electric (BEV) plus plug-in hybrid (PHEV) — unless otherwise noted.

Technical Specification Verification

Vehicle and product specifications — including battery capacity, range figures, charging speeds, motor output and dimensions — are verified through the following hierarchy:

1. Regulatory homologation filings: The definitive source for Chinese-market vehicle specifications.
2. Manufacturer official specifications: Published spec sheets and technical documentation.
3. Third-party testing: Independent range tests (WLTP, EPA, CLTC), charging-curve measurements and instrumented performance testing.
4. 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 is accompanied by the testing standard under which it was measured — CLTC, WLTP, EPA or NEDC. CLTC figures are typically 15–25% higher than EPA figures for the same vehicle; we do not mix standards within a single comparison without explicit conversion notes.

Review & Product Testing Standards

When EVsays publishes vehicle reviews, test drives or hands-on evaluations, we disclose whether the test unit was provided by the manufacturer, rented independently or accessed through a media fleet program. Test conditions that materially affect performance data are documented. Manufacturer-provided vehicles are accepted for evaluation only, with no guarantee of coverage or influence on conclusions.

Image & Multimedia Attribution

All images, videos, charts and data visualizations are sourced and attributed: official manufacturer imagery under fair use / editorial purposes; third-party photography licensed or used with permission; original EVsays content marked as such. We do not publish AI-generated images representing real vehicles or events.

Data Update & Refresh Policy

Evergreen content is reviewed and updated: monthly for sales trackers and market-share data, quarterly for company profiles and technology explainers, and event-driven for any page referencing a specific model or technology. Substantive updates update the “Last updated” date and add an Editor’s Note where conclusions change materially.

Limitations & Caveats

We are transparent about what our data can and cannot tell you. Chinese-market data (MIIT, CPCA) is reliable but subject to reporting lags and retroactive adjustments. Self-reported automaker figures — particularly for export markets — may be unaudited. Speculative content is clearly labeled as analysis or speculation. Forward-looking estimates include their basis and an acknowledgement of uncertainty.