What is ngk spark plug number br9es equivalent to in an iridium ngk plug?

The NGK spark plug number BR9ES is equivalent to the NGK iridium plug number CR9EIX. Both plugs are designed for similar applications, but the iridium version offers better durability and performance due to its finer center electrode and enhanced thermal conductivity. If you're considering an upgrade, the CR9EIX would be a suitable replacement for the BR9ES.