Spark plug · NGK
Equivalents for the NGK spark plug 6521
NGK 6521 is a spark plug. Find its 42 compatible and interchangeable spark plugs: cross-references for NGK, Bosch, Champion, Denso and every brand.
Buy this spark plug NGK 6521 — best retailers
Partner links: a purchase made through these links may earn us a commission, at no extra cost to you.
What can replace a NGK 6521 spark plug?
The NGK 6521 is interchangeable with: NGK BM7A, Bosch WS 5 E, Champion CJ4, Bosch WS 6 E, Bosch WS 7 E, Champion CJ6. These spark plugs share the same mounting (thread, seat) and heat range.
Cross-references and specifications are provided for guidance only. The wrench size can vary by brand, and some data is inferred from the plug code or an equivalent reference. Always check the vehicle manufacturer's recommendation before buying and fitting.