The NGK Iridium IX LFR6AIX-11 is a fine-wire iridium spark plug sold in a box of four. Its tapered cut ground electrode and 0.044 in (1.1 mm) gap are aimed at sharper starts, steadier idle and quicker throttle response than standard copper or platinum plugs. Iridium's high melting point and six-times-harder-than-platinum electrode resist fouling and wear, so the plugs hold their gap longer in turbocharged or high-mileage engines. Enthusiasts rate the Iridium IX line for smooth running and long service life, though some note it costs more than basic plugs and gains little on a stock engine. NGK's Ruthenium HX is the step up for those chasing maximum durability.
In stockReturn policy
Owners of the Iridium IX line generally report smoother idle, easier starts and long service life, and many buy it again at replacement time. Some say the benefit over cheaper plugs is small on a stock engine and question the higher cost.
The NGK Iridium IX spark plug is designed for performance enthusiasts. It is built for acceleration, fuel efficiency and durability. It offers extreme ignitability and strong anti-fouling.
The center electrode is made of fine iridium wire. Iridium is six times harder than platinum and has an extremely high melting point. The ground electrode has a tapered cut, which improves starting, idling and throttle response.
This box contains 4 plugs.
