GENUINE OEM NISSAN RB20 RB25 RB26 SPARK PLUG
The Nissan RB Engine spark plugs are a hit or miss, with so much misleading information on the internet the best way to get the correct spark plugs for your RB20DET RB25DET or RB26DETT engine is to use OEM Nissan plugs with the correct heat range for your performance orientation. (yes Nissan did offer alternative heat range spark plugs)
Platinum tipped spark plugs are the OEM standard for all the RB series engines; factory tuned engines require a heat range of 6 in most climates, extreme cold climates called for the heat range of 5 for easier cold starts because of the low risk of detonation (RB20/25 ONLY). The performance oriented and modified RB engines heat range 7 is what is recommended to run due to the higher boost levels, and leaner fuel mixtures of a non standard nissan ECU fuel mixture.
Copper core spark plugs are also available for the RB Series engines. These sparkplugs have a hotter richer spark due to the copper core however unlike the platinum spark plugs they do not last as long as the platinum tip plugs. the heat ranges are the same. heat range 6 for a stock to mildly (basic breather mods) RB engine. Heat range of 7 is what is recommended for the guys with higher boost levels, upgraded turbos, re-mapped ECM’s and competition vehicles.