Last updated: August 25, 2026
Every spec in this app carries its own source citation and, where relevant, its own sourcing notes - that's the record for any individual value. This page explains the patterns behind those citations: what the confidence labels actually mean, why two near-identical bolts sometimes carry different torques, and why a figure occasionally comes from one factory document instead of another. It's not a substitute for reading a specific record's own citation, and it's not a legal document - see the Automotive Disclaimer for that.
Every spec is tagged with one of four confidence levels. Two of them are in active use across this dataset today; the other two exist in the data model for situations that haven't come up yet, not as unused decoration.
Factory Verified means one Porsche factory document states the value directly, and no second document was found stating something different for the same fastener or spec. Cross Referenced means either two or more independent factory documents state the same value, or two documents disagree and both readings are recorded rather than one being silently discarded - see "Why two similar bolts show different numbers," below, for what that disagreement usually means. The two unused tiers, Community Verified and Needs Review, are reserved for a non-factory-sourced value awaiting confirmation and a transcription that couldn't be read with confidence, respectively - neither applies to any record in the app today.
One honest exception worth naming directly: a small number of records aren't sourced to a Porsche factory document at all - most have been superseded since, but the SC's firing order is a current example, sourced to Bentley Publishers' independently-published service manual because no owned factory document states it. None of the four confidence tiers describes "a single reputable non-factory source" cleanly. Those records are tagged Cross Referenced as the least-wrong fit, with the actual situation - what was checked, what wasn't found, and where the value actually comes from - spelled out in that record's own notes rather than left for the label alone to imply.
A record's detail page labels its citation either Factory Source or plain Source, automatically, based on whether the citation itself names a Porsche factory document. A citation to an independently-published manual (the Bentley example above) is labeled Source, not Factory Source - deliberately, so a citation never implies factory backing it doesn't actually have.
Porsche genuinely changed specific torque values during the production run this app covers, and this dataset records that directly rather than picking one figure to represent every year. When a spec's value is confirmed to have changed at a specific point - a new part, a running production change, a revised procedure - it becomes two separate records, each scoped to the years it actually applies to, rather than one record silently averaged or updated in place. If you see what looks like the same fastener with two different torques, check each record's own applicable years before assuming one of them is wrong.
Separately: when two factory sources state genuinely different figures for the same fastener with no clear production-change explanation - not a rounding difference, an actual disagreement - that gets recorded as a Cross Referenced spec with both readings stated in the notes, not resolved by guessing which source is right.
This dataset is built from more than one kind of factory document - the full workshop manual, and separate factory tech-spec booklets published for specific model years. Where they agree, either can be cited. Where they don't - most commonly because the workshop manual only prints a value in kpm and a tech-spec booklet states a directly-usable Nm figure for the same fastener, rather than one being a rounding of the other - the more directly-stated, more recently-published factory figure is used, and the reasoning is recorded in that specific record's own notes. This is never a silent substitution: if a value in this app doesn't match what you find printed in your own copy of the workshop manual, the record's notes will explain why, not leave you to wonder.
Every torque spec displays in both Nm and ft-lb, regardless of which unit the source actually printed. Exactly one of those two numbers is the source's own verbatim figure; the other is calculated from it, using standard, fixed conversion constants - never re-measured or re-rounded from a different intermediate value. The exchange icon next to the numbers marks this explicitly, and the "Factory Source"/"Source" line beneath it always states the real, verbatim figure and unit exactly as printed in the original document, so you can tell which of the two displayed numbers is the actual factory figure.
This page explains patterns across the dataset, not any single value. The authoritative record for a specific spec is always that spec's own citation and notes, visible on its own detail page. Read the Automotive Disclaimer before using any spec in this app for actual repair work.