# FilterEquiv

> Filter cross-reference tool with physical specs comparison.

## What this site does

FilterEquiv cross-references oil, fuel, air, and hydraulic filters across major manufacturers (Baldwin, Donaldson, Fleetguard, WIX, CAT, and more). Unlike other tools, we show the physical specifications (thread, gasket diameter, height, bypass pressure, anti-drainback valve) so users can verify that a substitute filter actually fits.

## How to use

Enter a filter part number (OEM or aftermarket) to see all known equivalents with their physical specs compared side by side.

## Data sourcing

All data comes from official manufacturer catalogs. Cross-references are built by combining multiple manufacturer interchange tables. Direct matches are confirmed by at least one source. Inferred matches are derived through transitive equivalence, limited to two hops.

## Pages

- /: Search tool (main entry point)
- /filter/{part-number}: Individual filter reference with equivalents and specs
- /cross/{brand-a}-to-{brand-b}: Brand-to-brand cross-reference tables
- /about: How we build our data
- /disclaimer: Legal disclaimer and accuracy information

## Contact

See /about for details.