Copper U-Groove Conventional; Patented U-Groove Design
DENSO's patented U-Groove spark plug enables complete combustion by allowing the spark to fill the gap created by the U shape. The ball of fire created in the U-Groove develops a larger and hotter flash front that virtually eliminates excessive fouling and erratic starts caused by poor fuel mixtures.

Even DENSO's "standard" spark plug is something special. The innovative design that helped to make DENSO spark plugs famous, the U-Groove plug employs a unique, channeled ground electrode designed to generate a larger spark nucleus at the point of ignition. Greater spark energy than ordinary plugs means improved flame travel, producing more complete, consistent, and efficient combustion.

Features:
  • 100 percent pre-fired to ensure reliable operation
  • Copper core center electrode for superior thermal conductivity
  • Unique five-rib insulator reduces flashover
Benefits:
  • Patented U-groove ground electrode design fires leaner mixtures than conventional plugs
  • Precision machine-rolled threads reduce seizing and cross-threading in delicate aluminum heads
  • Wide range of part numbers for thousands of applications, including classic and collector cars
  • Greater Fuel Efficiency

Spark Plug Type Performance Differences

Center Electrode Core MaterialCopper
Center Electrode Tip MaterialNickel
Gap Size1.1 MM
Ground ConfigurationStandard
Ground Electrode Core MaterialNickel
Ground Electrode Quantity1
Ground Electrode Tip DesignU-Groove
Hex Size16.0
Manufacturer Heat Range20
Reach19.00 mm
Resistance5000
Seat TypeFlat
Thread Diameter14.00 MM
Alternate/OEM Part Number(s): 000018F220, 18218200016, 18218200018, 2240101P16, 2240102P16, 30520467, 5958798, 9117565, 9139643, 9807956148, 9807956158, 9807956158S, F22018110, F22118110, Q20PRU11