More Information for DENSO 3421
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DENSO 3421
  • ($6.40) x4 Warehouse
  • ($6.44) x1 Warehouse
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DENSO 3421 Specifications
Center Electrode Core MaterialCopper
Gap Size1.1 MM
Ground ConfigurationStandard
Ground Electrode Core MaterialNickel
Ground Electrode Quantity1
Ground Electrode Tip DesignPlatinum Chip
Hex Size16.0
Manufacturer Heat Range20
Reach26.50 MM
Seat TypeFlat
Thread Diameter14.00 MM
Iridium Long Life
The DENSO Iridium Long Life plug is fast becoming the standard for today's high-tech engines. Employing a revolutionary new 360 laser-welding process, DENSO has created a spark plug unlike anything on the market today. Designed for durability under the most extreme conditions, DENSO's patented Iridium alloy is six times harder and eight times stronger than conventional Platinum and can handle temperatures in excess of 4,000F. DENSO was able to shrink the center electrode to 0.7mm, dramatically improving ignitability and longevity. You'll enjoy more horsepower, faster easier starts, fewer misfires under heavy loads, plus better conservation of fuel at all times!

  • Fine-wire iridium center electrode
  • Platinum ground electrode
  • 360 degree laser-welded spark tip
  • Endures extreme temperatures greater than 4,000 degrees F (associated with high-performance ignition and special fuel systems)
  • Sustained spark performance over 100,000 miles
  • Withstands higher pressures and temperatures
  • Reduced spark plug wear and erosion
  • Lasts up to three times as long as conventional plugs
  • Tapered cut improves firing performance by reducing quenching

Which Spark Plug Is Right For You?

Material Cost Performance Lifespan Highlights
$$$ · Ultimate Ignitability & Durability
· Fast Throttle Response & Best Cold Starts
$$ · Improved Starts & Acceleration
· More Power & Better Fuel Economy
Double Platinum
$$ · Improved Efficiency
· Good For Waste Spark Systems
$ · Reduced Carbon Build-Up
· Good for Coil-On-Plug Systems
$ · Good Conductor
· Least Durable

How To Replace DENSO Spark Plugs

Alternate/OEM Part Number(s): 12120032138, 12120037663, 12122158253, 12293PHMA01, 12565996, 12788884, 224015M016, 22401AA580, 22401CK81B, 22401EA016, 22401ZH016, 306503790, 306508430, 307138590, 307518050, 307518060, 312161830, 32010632, 55564748, 9091901191, 9091901235, 90919A1002, MN158596, SK20HR11

Warranty Information:
No Warranty