NGK LKR7BHX 94705 Ruthenium HX Spark Plugs

Description

NGK Ruthenium HX LKR7BHX (94705) Spark Plug — Specifications, Features & Applications

The NGK LKR7BHX, identified by stock number 94705, belongs to NGK’s Ruthenium HX family of high-ignitability spark plugs. It is designed for modern engines, particularly turbocharged and direct-injection applications where the ignition system operates under higher cylinder pressures and demanding combustion conditions. The plug features a 12 mm thread diameter and 26.5 mm reach, a long-reach configuration found in various Hyundai-Kia, Jeep, Mitsubishi, Mercedes-Benz and Volkswagen applications.

Rather than using the Double Fine Electrode (DFE) configuration found on some other Ruthenium HX models, the LKR7BHX incorporates NGK’s Projected Square Platinum Electrode (PSPE) technology. Its cut-back, square-shaped platinum ground electrode leaves more of the spark area exposed to the air-fuel mixture. This design helps promote reliable ignition and consistent combustion, especially in turbocharged engines where cylinder pressure and mixture conditions can change significantly.

Technical Specifications

Key Features

Projected Square Platinum Electrode (PSPE) technology. The LKR7BHX features a cut-back, square-shaped platinum ground electrode that leaves a greater portion of the spark exposed to the combustion mixture. This configuration is particularly beneficial in turbocharged and direct-injection engines, where combustion pressures and air-fuel conditions can fluctuate considerably.

Extended 26.5 mm reach. The long-reach design places the firing end at the correct position within the combustion chamber for engines specified for this plug. Proper electrode positioning can promote effective flame-kernel development and help maintain dependable ignition.

Ruthenium fine-wire center electrode. NGK’s ruthenium alloy center electrode is engineered to withstand electrical erosion and high operating temperatures. Its fine-wire construction helps concentrate the ignition energy at the spark gap, supporting stable and consistent spark performance over time.

Platinum cut-back ground electrode. The platinum PSPE ground electrode combines durability with a design focused on improved ignitability. Its cut-back profile reduces the amount of the electrode surrounding the spark, allowing the ignition point to interact more effectively with the air-fuel mixture.

Copper-core construction. A high-purity copper core assists with efficient heat transfer from the firing end of the plug. This helps maintain appropriate operating temperatures and supports the heat-range-7 specification of the LKR7BHX.

Corrosion-resistant metal shell. NGK’s trivalent metal plating helps protect the spark plug shell against corrosion and reduces the risk of thread seizure during installation and removal. The corrugated ceramic insulator also helps minimize the possibility of flashover and keeps the ignition energy focused toward the spark gap.

High-strength ceramic insulator. The pure alumina silicate ceramic insulator provides electrical insulation while being designed to withstand the high temperatures, pressure and vibration encountered inside modern combustion engines.

Vehicles Using NGK LKR7BHX (94705)

The NGK LKR7BHX 94705 is specified for a variety of vehicle applications, including turbocharged engines from Hyundai, Kia, Jeep and Mitsubishi, as well as selected Mercedes-Benz, Smart and Volkswagen applications using the required 12 mm long-reach configuration.

Commonly referenced applications include:

Because the LKR7BHX 94705 is used across multiple manufacturers and engine configurations, the correct application can differ according to the vehicle’s model year, engine, trim level and engine code. Even vehicles carrying the same model name may use different spark plugs depending on the engine specification.

Always verify the existing spark plug part number, vehicle owner’s manual or VIN before purchasing. Matching the thread size and reach alone does not guarantee that a spark plug is suitable for a particular engine; heat range, electrode design and other specifications must also match the manufacturer’s requirements.