BMS "recommends"
HKS, which accounts for its favorable rating and preference. If you pick an NGK in a similar grade, there is little difference to the
HKS. Compare the specs here:
HKS M-Series Super Fire Racing
spark plugs are high-performance Iridium plugs designed to handle advanced levels of tuning and provide Improved ignition performance, durability, and anti-carbon build-up
HKS® M-Series Super Fire
Spark Plugs Feature 0.6mm Iridium Alloy Center ElectrodeIridium...
burgertuning.com
They are basically identical... materials and construction. In fact, they are probably the exact same plug.
HKS specializes in aftermarket parts of all kinds, catering to the performance crowd. They don't manufacture their own
spark plugs. NGK actually is the OEM for
HKS, which gets their own private label and performance aura tacked on... along with their markup.