NGK BR9ESequivalent & cross reference

The NGK BR9ES spark plug is directly equivalent to DENSO W27ESR-U and DENSO IW27, confirmed by shared applications in both manufacturers' official catalogues.

Equivalents

Part	Shared applications	Agreement
DENSO W27ESR-U	13	87%
DENSO IW27	13	87%

Verified fitments for the NGK BR9ES

Aprilia RS 50 (1999–2005)
Yamaha DT 125 R (1988–2003)
Yamaha TDR 250 (1988–1992)

Equivalence confirmed by 3 independent sources, last verified 22 July 2026. Always confirm fitment against your owner's manual.