NGK Ruthenium HX Spark Plug Box of 4 (LKR6AHX)

This is a box of four NGK Ruthenium HX spark plugs, part number 91356. These are designed for modern engines that require high ignitability, like your 2011 Hyundai Elantra. They feature NGK's patented Ruthenium technology, which uses advanced tip designs to offer improved performance and a longer lifespan compared to standard plugs.

The Ruthenium HX plugs have a 0.4mm Ruthenium alloy fine wire center electrode and a 0.4mm platinum fine wire ground electrode. This Double Fine Electrode (DFE) design helps concentrate spark energy, leading to a more complete fuel burn. You might notice a quicker throttle response, a smoother idle, and better cold starts. The pure alumina silicate ceramic insulator helps with heat transfer, and the trivalent metal plating on the plug body helps prevent corrosion and seizing.

These are a solid option if you're looking for an aftermarket plug that uses the latest OE technology. They're built to handle a wider range of air-fuel ratios, which can be beneficial in both rich and lean engine conditions.