NGK 1637 Spark Plug

NGK Laser Iridium Spark Plug 1637

NGK Laser Iridium Spark Plug 1637 is an OE-style ignition component built for precise spark delivery and stable engine performance. This NGK Laser Iridium Spark Plug is specified for select Kia and Hyundai applications, including Optima, Magentis, Rondo, Santa Fe, Genesis, and Borrego models.

Key Features

• Laser iridium center electrode tip for consistent ignition performance
• Standard ground electrode design with a single ground electrode
• 5,000 ohm resistance for ignition system compatibility
• Pre-gapped at 0.044 in. for listed applications
• 14 mm thread diameter, 26.5 mm reach, and flat seat design
• Non-removable nut terminal for secure connection
• NGK part number 1637, also identified as ILFR5B11

Product Details

NGK builds this Laser Iridium Spark Plug as an OE replacement for vehicles that call for precise ignition timing and dependable combustion. The iridium center electrode tip supports consistent spark delivery, while the nickel ground electrode and copper core help maintain stable operation under normal service conditions. For shoppers searching for a spark plug for 2006-2010 Kia Optima, 2007-2010 Kia Magentis, or 2007-2012 Kia Rondo, NGK 1637 matches the listed fitment and factory-style specifications. It also fits select Hyundai Genesis, Santa Fe, and Kia Borrego applications with the notes shown below.

NGK’s OE manufacturing background and broad North American coverage make this a practical choice for drivers replacing worn plugs on vehicles that require the specified heat range, reach, and gap. This part cross-references DENSO Auto Parts (e.g., 4505) for the same application.

Common Issues This Part Can Address

• Rough idle caused by worn spark plug electrodes
• Hard starting from weakened ignition performance
• Misfire conditions related to plug wear or incorrect gap
• Reduced throttle response from inconsistent spark delivery
• Fuel economy loss tied to degraded ignition efficiency

Installation Notes and Fitment

• Fits 2007-2012 Kia Rondo, N/A; Gap 0.044"; Actual OE Manufacturer; 100,000 mi OE Mfr Recommended Service Interval; Laser Iridium Spark Plug
• Fits 2007-2010 Kia Magentis, N/A; Gap 0.044"; Actual OE Manufacturer; 100,000 mi OE Mfr Recommended Service Interval; Laser Iridium Spark Plug
• Fits 2006-2010 Kia Optima, N/A; Gap 0.044"; Actual OE Manufacturer; 100,000 mi OE Mfr Recommended Service Interval; Laser Iridium Spark Plug
• Fits 2009 Hyundai Genesis, N/A; Build Date Before 5/1/2008; Gap 0.044"; Actual OE Manufacturer; 100,000 mi OE Mfr Recommended Service Interval; Laser Iridium Spark Plug
• Fits 2008-2009 Hyundai Santa Fe, N/A; Gap 0.044"; Actual OE Manufacturer; 97,500 mi OE Mfr Recommended Service Interval; Laser Iridium Spark Plug
• Fits 2009 Kia Borrego, N/A; To 5/15/2008; Gap 0.044"; Actual OE Manufacturer; 100,000 mi OE Mfr Recommended Service Interval; Laser Iridium Spark Plug
• Fits 2007 Hyundai Santa Fe, N/A; Gap 0.044" OE Manufacturer; 60,000 mi Service Interval; Laser Iridium Spark Plug

Verify engine application, build date, and plug gap before installation. Use the listed 0.044 in. gap and torque to the vehicle manufacturer’s specification for the best results on compatible Kia Optima, Kia Rondo, and Hyundai Santa Fe applications.

Quality Assurance

NGK is a long-established OE supplier and spark plug manufacturer with extensive coverage across domestic and import vehicles in North America. Part number 1637 is built to OE-style standards for durability and consistent operation in the listed applications.