/live/media/NG/NG_91121_Fro.jpg)
OE Quality
60-Day Returns
NGK 91121 Spark Plug
NGK Laser Iridium Spark Plug for Smart Fortwo
The NGK Laser Iridium Spark Plug 91121 is built for precise ignition performance in select Smart Fortwo applications. It combines an iridium center electrode tip with a nickel ground electrode design to support consistent spark delivery and stable combustion.
Compatible with 2016-2017 Smart Fortwo, this NGK spark plug is specified with a 0.028 in. pre-gap and a flat seat design for the listed OE-style application. The 91121 part number is also identified as ILKAR7J7G.
Key Features
- Laser Iridium spark plug from NGK
- Iridium center electrode tip material for durable spark performance
- Copper center electrode core and nickel ground electrode core
- 0.028 in. pre-gap size
- 5000 ohm resistor design
- Flat seat, 12 mm thread diameter, 14 mm hex size
- Non-removable nut terminal type
- Heat range 7 specification
Product Details
NGK is a long-standing OE supplier for domestic and import vehicles in North America, and this Laser Iridium Spark Plug reflects that OE-focused engineering approach. The 91121 spark plug is built to the listed dimensions and electrical specifications, including a 26.5 mm reach and standard ground configuration, for direct service on the specified Smart Fortwo model years. Use part number 91121 when verifying the correct replacement, and reference ILKAR7J7G as the manufacturer part number.
This part cross-references Dorman - HELP 91121 for the same application.
What It Helps Address
- Misfires caused by worn or fouled spark plugs
- Hard starting from weak ignition output
- Rough idle related to degraded plug performance
- Reduced combustion consistency under normal driving conditions
- Service replacement needs at the OE-recommended interval for the listed Smart Fortwo application
Installation Notes
Verify the vehicle application before installation and confirm the plug gap matches the listed 0.028 in. specification. Check thread diameter, reach, seat type, and terminal style against the original plug before service. For 2016-2017 Smart Fortwo ignition service, follow the vehicle manufacturer’s torque and service procedures.
Quality Assurance
NGK manufactures spark plugs for a wide range of automotive applications and supports OE-level standards for durability and operational performance. The 91121 Laser Iridium Spark Plug is backed by NGK’s manufacturing and distribution expertise in North America and globally.
| Brand | NGK |
|---|---|
| Part Number | 91121 |
| Position | Laser Iridium Spark Plug |
| Resistance | 5000 |
| Ground Electrode Tip Design | Standard |
| Ground Configuration | Standard |
| Ground Electrode Core Material | Nickel |
| Electrical Terminal Type | Non-removable nut |
| Center Electrode Core Material | Copper |
| Center Electrode Tip Material | Iridium |
| Pre-Gap Size | .028 |
| Ground Electrode Quantity | 1 |
| Hex Size | 14 |
| Insulator Height | 51.00 |
| Manufacturer Heat Range | 7 |
| Seat Type | Flat |
| Reach | 26.5 |
| Thread Diameter | 12.00 |
| Resistor Type | Yes |
| Part Number | Ilkar7j7g |
| Stock Number | 91121 |
This part fits 2 vehicles. Search below:
| Year | Make | Model | Liters | Cylinders | Position | Notes |
|---|---|---|---|---|---|---|
| 2017 | Smart | Fortwo | 0.9L | L3 | N/A | 0.028" gap with OE manufacturer at 30,000 mile recommended service interval.; Laser Iridium Spark Plug |
| 2016 | Smart | Fortwo | 0.9L | L3 | N/A | 0.028" gap with OE manufacturer at 30,000 mile recommended service interval.; Laser Iridium Spark Plug |
* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
This part directly replaces or is cross-referenced with the following part numbers:
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.