About Mechanics Online & Data Sources

Mechanics Online is a free automotive knowledge and tools site for car owners, mechanics, technicians and people researching vehicles.

Data sources

Vehicle specifications and fuel economy: U.S. Environmental Protection Agency and Department of Energy, fueleconomy.gov (public domain). Figures are EPA estimates for vehicles sold in the United States.
VIN decoding and recalls: U.S. National Highway Traffic Safety Administration (NHTSA) vPIC and recalls APIs, queried directly from your browser.
OBD2 codes: generic code definitions follow SAE J2012 / ISO 15031-6. Explanations, causes and diagnostic steps are written by our editors as general guidance.
Calculators: standard engineering formulas, shown on each tool page.

Important

Everything here is general information. Vehicles differ, and specifications change between markets and production dates. Always confirm values and procedures in the manufacturer's service information, and use a qualified technician for safety-critical work such as brakes, steering, airbags and fuel systems.