Find the right spark plug in seconds.

Search vehicle applications, decode any part number, and compare every major manufacturer — copper to ruthenium, ranked honestly.

Make

Model

Year

Engine

Reads NGK, Denso, Champion, Bosch, Autolite, ACDelco, Pulstar — plus NGK glow plugs and Denso industrial plugs.

Returns every brand's equivalent with compatibility ratings and a side-by-side difference viewer.

Part Number Decoder

Every part number is a spec sheet in disguise. We break it apart — thread, heat range, reach, electrode, gap — using each manufacturer's official numbering system.

Try:

Decoder rules transcribed from manufacturer numbering charts, including NGK glow plug and Denso industrial systems. Modern laser-iridium long codes are decoded best-effort and labeled. Motorcraft and 4-digit stock numbers are assigned catalog numbers, not coded. Always confirm against the current catalog.

Metal Tiers Compared

Electrode metal is what you're really paying for. Harder metal → finer electrode → stronger spark for longer. Match the tier to how long you'll keep the vehicle.

Copper / Nickel

20–30k mi · $

Best for: Older engines, HEMI OE, tuners

ProsBest conductivity, cheapest per plugConsFastest wear — priciest per mile

Platinum

60k mi · $$

Best for: Commuters upgrading from copper

Pros2–3× copper life for a few dollars moreConsOutclassed by iridium at OE level

Double Platinum

80–100k mi · $$

Best for: Waste-spark ignition systems

ProsBoth electrodes protectedConsNever downgrade if your engine specs it

Iridium

80–120k mi · $$$

Best for: Nearly every modern engine (OE)

ProsFinest electrode — best ignition qualityConsCosts more up front

Ruthenium

100k+ mi · $$$$

Best for: Turbo & direct-injection keepers

ProsBest oxidation resistance madeConsPremium price, limited lineup

Head-to-head by the numbers

Longevity

Copper / Nickel25

Platinum55

Double Platinum75

Iridium90

Ruthenium97

Performance

Copper / Nickel70

Platinum78

Double Platinum82

Iridium93

Ruthenium95

Cost value

Copper / Nickel95

Platinum85

Double Platinum78

Iridium70

Ruthenium60

Ignition quality

Copper / Nickel72

Platinum80

Double Platinum84

Iridium94

Ruthenium96

Efficiency

Copper / Nickel70

Platinum78

Double Platinum82

Iridium92

Ruthenium95

Spark plug questions, answered

The basics of finding, comparing and replacing spark plugs. Dig deeper on the blog.

How do I find the right spark plug for my vehicle?

Use the vehicle finder at the top of this page — enter your year, make, model and engine, and it returns the correct spark plug along with every brand's equivalent and typical pricing.

Can I use a different brand of spark plug than the original?

Almost always, yes — as long as the replacement matches the physical fit (thread, reach, seat) and the correct heat range for your engine. Our cross-reference tool finds true equivalents across NGK, Denso, Champion, Bosch, Autolite and ACDelco. See the full explanation.

How often should spark plugs be replaced?

It depends on the metal: copper plugs last about 20,000–30,000 miles, platinum around 60,000, and iridium or ruthenium roughly 100,000 miles. Always confirm against your owner's manual. More in this guide.

What's the difference between copper, platinum, and iridium plugs?

The electrode metal determines lifespan and spark quality. Harder metals like iridium erode slower and allow a finer electrode for a stronger spark, so they last far longer than soft copper. Full comparison in the tier guide.

How do I read a spark plug part number?

Each number encodes thread size, reach, heat range and tip design — but every brand numbers differently. Paste any plug into the decoder to read its specs automatically, or see the numbering guide.

How accurate are the cross-references?

Cross-references are matched on physical fit and a normalized heat range — the specs that actually decide whether a plug is interchangeable — not on part numbers, which don't line up across brands. Always verify against your owner's manual before buying.