NGK / SPARK PLUG CROSS-REFERENCE
NGK 4577 Cross Reference
Explore the listed cross-reference options for NGK 4577. References on this page include Autolite AR72 and Denso W22S-U.
NGK 4577 Specifications
RECORDED DATAThe recorded data lists a thread diameter of 14.0 mm, a thread reach of 9.5 mm and a hex size of 20.8 mm.
- Thread diameter
- 14.0 mm
- Thread reach
- 9.5 mm
- Hex size
- 20.8 mm
Listed Replacement Part Numbers4
1–4 of 4| Manufacturer | Part number |
|---|---|
| Autolite | AR72View cross reference |
| Denso | W22S-UView cross reference |
| Denso | W22SUView cross reference |
| NGK | R5670-7View cross reference |
Always confirm thread size, reach, seat type, heat range, and gap against the engine manufacturer’s recommendations before fitting a replacement.
What to Check Before Choosing a Replacement
Use the recorded dimensions as a starting point, not as a fitment guarantee.
Dimensions and Seat Type
Compare thread diameter, reach and seat type with the engine manufacturer's requirements. Similar-looking plugs can have different dimensions or seats.
Heat Range, Gap and Engine Application
A cross-reference match alone does not confirm heat range, electrode gap or engine application. Check the manufacturer's application catalogue and installation guidance before fitting another part number.
Read the spark plug specification guide