Data guide

Why car specifications vary by market, trim and model year

Two credible sources can publish different figures for the “same” model. Often they are describing different versions, standards or production dates.

One badge can cover several vehicles

Automakers adapt vehicles for emissions rules, fuel quality, taxes, climate, road conditions and customer demand. A familiar model may receive a smaller engine in one country, a different transmission in another, or market-specific suspension and safety equipment.

Even within one market, the same sales name may span multiple body styles and drivetrains. The vehicle identification number and the manufacturer documentation for that market are better identifiers than the badge alone.

Measurement methods change the result

FigureWhy two sources may differ
Fuel consumptionDifferent drive cycles, temperatures and unit conventions
PowerDifferent standards, corrections or hp/PS/kW conversion
Cargo volumeDifferent loading blocks or measurement boundaries
Curb weightDriver, fuel and standard equipment definitions vary
AccelerationSurface, weather, rollout and vehicle condition differ

How to make a defensible comparison

Start with the market and model year, then match body style, engine code or displacement, transmission and driven wheels. Preserve the original unit when possible and record the conversion separately. If two credible values still conflict, show the scope of each instead of averaging them.

  • Prefer a manufacturer manual, homologation record or government label tied to the exact version.
  • Record the source date and market alongside the value.
  • Do not transfer a specification from a similar-looking trim without evidence.
  • For safety, repair, towing or registration decisions, verify against the exact VIN.

Explore the catalog

Apply these concepts to real model-generation and body-style pages in the Autotras catalog.

Sources and editorial note

This guide explains general engineering distinctions. Exact behavior and terminology can differ by manufacturer, market and model year; check the owner’s manual and specifications for the exact vehicle.

  1. U.S. EPA — Fuel Economy test procedures — explains controlled test cycles behind U.S. ratings
  2. European Commission — WLTP — European vehicle emissions and consumption framework
  3. Autotras data methodology — how this catalog retains, normalizes and qualifies vehicle records

See how we handle vehicle data in our data methodology, or report a correction.