Cross-reference any part number

What is a part number cross-reference?

A cross-reference matches one manufacturer's part number to every equivalent part made by other brands. The killer example: a Bugatti Veyron oil filter is the same physical part as a Volkswagen Touareg oil filter — same dimensions, same thread, same filtration spec — but the Bugatti badge adds a 10× markup. The cross-reference reveals every brand (Bosch, Mahle, Mann, Hengst, etc.) that sells the equivalent so you can buy the cheapest one without compromising fitment.

Why cross-referencing matters

Most car owners and even some mechanics order by the dealer-issued OEM part number out of habit. That part number is just a label — under the hood, the actual filter or brake pad or alternator is manufactured by a Tier-1 supplier (Bosch, Mahle, NGK, ZF, Sachs, Mann, Hengst) and sold to the carmaker who slaps their logo on the box. When you cross-reference, you find the Tier-1 supplier's own version of the part — same factory, same quality, no dealer markup.

Typical savings on routine maintenance: 50–90%. On a $1,200 dealer brake job, that's $600–$1,000 staying in your pocket. To make sure the equivalent actually fits, find car parts by VIN first — it's also the best way to avoid the mistakes behind why auto parts get returned.

How to find your part number

• On the part itself. Oil filter housings, air filter frames, brake pad backing plates, alternator cases — most parts have the manufacturer's number molded or printed directly on them.
• On the dealer invoice. Repair estimates and final bills always list OEM part numbers next to the line items.
• In the owner's manual. The maintenance section often lists oil filter, air filter, spark plug, and brake pad part numbers.
• On the box of a replacement you already bought. Both the OEM number and the aftermarket brand's own number are usually printed.
• Online from parts diagrams. RockAuto, FCP Euro, ECS Tuning, and dealer parts diagrams all use the same OEM numbering scheme.

The tool accepts both formats: OEM numbers like 06A115561B (Audi/VW oil filter) and aftermarket references like WK853/3X (Mahle) or V10-0316 (Vaico). Either direction works.

Common cross-reference scenarios

• European cars are the biggest opportunity. BMW, Audi, Mercedes, Porsche all share core parts with their cheaper sister brands (VW, Mini, Smart). Markup on the premium-badge box can be 5–10×.
• Common-platform parts. The VW MQB platform underpins Audi A3, Golf, Tiguan, Skoda Octavia, SEAT Leon — same maintenance parts across all of them.
• Workshop parts ordering. Workshops buy by OEM number from their parts distributor; the distributor cross-references to the cheapest equivalent Tier-1 brand in stock. You can do this yourself.
• Older vehicles (15+ years). Dealer prices on out-of-production parts get extreme. The aftermarket equivalent often costs a fraction.

Where the data comes from

Cross-reference results are powered by TecDoc, the industry-standard parts catalog used by 100,000+ workshops and parts retailers worldwide. Every match in the results is a verified physical equivalent — not an algorithmic guess. TecDoc is the same data your local independent mechanic uses when sourcing parts.