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NGK 4085 Spark Plug
| Brand | NGK 4085 |
|---|---|
| Center Electrode Core Material | Copper |
| Center Electrode Tip Material | Iridium |
| Electrical Terminal Type | Removable Nut |
| Ground Configuration | Standard |
| Ground Electrode Core Material | Nickel |
| Ground Electrode Quantity | 1 |
| Ground Electrode Tip Design | Taper Cut |
| Hex Size | 13/16 |
| Insulator Height | 55.00 |
| Manufacturer Heat Range | 6 |
| Part Number | BPR6HIX |
| Pre-Gap Size | .032 |
| Reach | .5 |
| Resistance | 5000 |
| Seat Type | Flat |
| Stock Number | 4085 |
| Thread Diameter | 14.00 |
| Product line | Iridium IX Spark Plug |
| Fits | Hyosung, Yamaha, Honda, Suzuki, Renault, Opel, Volvo, Citroen, Saab, Triumph, Mercedes-Benz, Porsche, Oldsmobile, and Buick · 4 vehicles |
Iridium tip. Promotes consistent spark performance and long service life.
Copper core. Helps transfer heat efficiently for stable operation.
Taper-cut electrode. Improves ignition efficiency with a precise spark path.
Cross-references DENSO Auto Parts 4085, 999-06910-X9-008 and 4200 for the same application. See all 13.
NGK Iridium IX Spark Plug 4085
NGK Iridium IX Spark Plug 4085 is built for precise ignition performance in classic Buick Skylark and Oldsmobile Cutlass applications. It combines an iridium center electrode, a nickel ground electrode, and a 0.032-inch pre-gap for consistent spark delivery.
Key Features
- Iridium center electrode tip material for stable ignition performance
- Copper center electrode core for efficient heat transfer
- Nickel ground electrode core with standard ground configuration
- Taper-cut ground electrode tip design for focused spark exposure
- 5000 ohm resistance for ignition system compatibility
- Flat seat, 14.00 mm thread diameter, and 0.5-inch reach
- 13/16 hex size with removable nut terminal type
- Manufacturer heat range 6
Product Details
The NGK Iridium IX Spark Plug line is engineered for drivers who want a modern spark plug design with OE-focused construction. Part number 4085 uses an iridium tip to support consistent ignition performance, while the copper core and nickel ground electrode help manage heat and durability in service. This spark plug is listed for 1961-1962 Buick Skylark and 1962-1963 Oldsmobile Cutlass applications, making it a direct-fit choice for select classic GM vehicles. This part cross-references DENSO Auto Parts 4085 for the same application.
Common Issues It Can Address
- Hard starting caused by worn spark plug electrodes
- Misfire from inconsistent spark delivery
- Rough idle related to aged ignition components
- Reduced throttle response from degraded plug performance
- Maintenance replacement for select Buick Skylark and Oldsmobile Cutlass ignition service
Installation Notes and Tips
Verify the specified gap before installation and confirm the plug matches the vehicle’s thread diameter, reach, seat type, and heat range. For fitment, use Fits 1961-1962 Buick Skylark and Fits 1962-1963 Oldsmobile Cutlass exactly as listed. Check the removable nut terminal style against the ignition lead connection before tightening to specification.
Quality Assurance
NGK is a long-established OE spark plug supplier with broad coverage across domestic and import vehicles, motorcycles, marine engines, and small engines. Its North American manufacturing and distribution network supports consistent product availability and OE-oriented quality control.
| Year | Make | Model | Liters | Cylinders | Position | Notes |
|---|---|---|---|---|---|---|
| 1963 | Oldsmobile | Cutlass | 3.5L | V8 | N/A | Spark Plug with a 0.035-inch gap; Iridium IX Spark Plug |
| 1962 | Buick | Skylark | 3.5L | V8 | N/A | Spark Plug with a 0.035-inch gap; Iridium IX Spark Plug |
| 1962 | Oldsmobile | Cutlass | 3.5L | V8 | N/A | Spark Plug with a 0.035-inch gap; Iridium IX Spark Plug |
| 1961 | Buick | Skylark | 3.5L | V8 | N/A | Spark Plug with a 0.035-inch gap; Iridium IX Spark Plug |
| No rows match your filter. | ||||||