Evidence and scope

Sources behind the refreshed guides.

The refreshed articles identify the sources used for their specific rules, methods and documentation checks. Government publications explain applicable rules; a manufacturer support library helps locate the documents for a model and serial number. Neither is a current lender, insurance, maintenance or valuation quote.

Content review date: October 16, 2026. Original publication dates of the external sources may be earlier. A link to a manual library is not a claim that every serial-specific manual has been independently reviewed.

Read the editorial policy and calculator methods for the limits of this resource.