About CarPartSizes

CarPartSizes is a static fitment reference for US passenger vehicles. It exists to answer one question before a driver buys a replacement part: what size or specification fits my exact year, make, and model?

The site covers consumable parts — parts a driver buys and replaces themselves without a shop visit. Each lookup page shows the checked specification, the sources that back it, and any caveats that matter before checkout. Fields that have not been confirmed against a real source are labeled as unverified rather than filled in with guesses.

What parts are covered

• Wiper blade sizes Driver, passenger, and rear blade lengths with connector type notes. Cross-checked against owner manuals and official blade manufacturer guides.
• Engine oil specs Capacity, viscosity grade, OEM approval code, and filter part number by engine. Checked against owner manual service schedules and manufacturer fill charts.
• Cabin air filters Part number by year, make, model, and body style. Cross-checked against part manufacturer fitment catalogs.
• Engine air filters Part number by year, make, model, and engine. Cross-checked against part manufacturer fitment catalogs.

Coverage expands as source records are checked. The current focus is on model years 2010 and later for US-market vehicles.

How fitment data is verified

Every published fitment field traces to at least one checked source — a document or page that was reviewed and noted before the page went live. The hierarchy of source trust is:

1. Owner manuals and OEM documentation — the manufacturer's own specification for that vehicle. Highest weight.
2. Official part manufacturer guides — Bosch, TRICO, Mobil 1, Fram, Denso, and similar. Cross-checked against OEM records.
3. Retailer fitment pages — AutoZone, O'Reilly, NAPA, and similar. Used for corroboration only, never as the sole source for a published fact.

A field backed only by retailer data is held at "needs review" and labeled on the page. A field where credible sources disagree is withheld from the published page until the conflict is resolved. No AI or automated inference is used to generate fitment values — every non-null field traces to a human-checked source.

Full methodology →

How uncertainty is labeled

Pages show three confidence states:

• Verified — core fields are supported by checked primary or corroborating sources.
• Needs review — useful data exists but one or more fields need stronger confirmation. The uncertain fields are labeled on the page.
• Unverified — a specific field (rear wiper, connector type, filter part number) has not been confirmed by a checked source. Displayed as "Unverified" rather than left blank or guessed.

What the site does not do

• No VIN lookup, license plate lookup, or OBD diagnostics.
• No repair advice, repair cost estimates, or mechanic referrals.
• No parts sales, checkout, or marketplace.
• No saved garage or user accounts.
• No AI-generated fitment verdicts or inferred specifications.

Corrections and feedback

If a published page shows a wrong size, a stale source, or a missing caveat, use the contact page and include the page URL, the vehicle, the field that looks wrong, and the source that supports the correction. Corrections with a verifiable source are reviewed and applied to the data record.