Shopping outside the US? International Shipping is now available!


Denso NP3421 Iridium Long Life Spark Plug - Direct Fit

Part Number: NP3421 Manufacturer Number: 3421

Denso NP3421 Iridium Long Life Spark Plug - Direct Fit

NP3421 3421
$22.12 $26.10 You Save: $3.98 (15%)
Add to Cart

Availability: In Stock Ships out in Same day - 1 business day

Savings Available
  • Only from APW Rewards
Savings Available
  • Only from APW Rewards

Product Details


Denso's Premium Class Extra Long Life Iridium Spark Plugs is fast becoming the standard for today's high-tech engines. Employing a revolutionary 360 degrees 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 6 times harder and 8 times stronger than conventional platinum and can handle temperatures in excess of 4,000 degrees Fahrenheit.

  • 14 mm thread size
  • 26.5 mm reach
  • 0.63 in. hex size
  • 0.04 in. gap size
  • Gasket seat style
  • Resistor plug type
  • 0.7 mm fine wire iridium tipped center electrode
  • Platinum tipped ground electrode
  • Solid terminal
  • Heat range 20

  • Designed with heavy duty insulator that provides unparalleled dielectric strength and thermal conductivity under extreme temperatures
  • Five-rib design prevents flashover while decreasing voltage loss
  • Copper glass seal bonds the center electrode and insulator together for a gas-tight seal
  • Platinum center electrode utilizes platinum to shrink the surface area of the center electrode tip for maximum firing performance and minimum voltage requirements
  • Platinum ground electrode resists gas and electrical erosion and corrosion extending service intervals to 60,000 miles


  • Series: Denso Iridium Long Life
  • Product Fit: Direct Fit
  • Quantity Sold: Sold Individually
  • Electrode Core Material: Iridium
  • Plug Type: Resistor
  • Anticipated Ship Out Time: Same day - 1 business day
  • Electrode Tip Material: Platinum
  • Gap Size: 0.044 in.
  • Reach: 26.5 mm
  • Thread Size: 14 mm
  • Warranty: 1 year Denso limited warranty

$22.12 $26.10

You save $3.98 (15%)

Add to Cart

Availability: In stock

Ships out in Same day - 1 business day
Lowest Price guarantee

Find a lower price on this Denso product? We'll match it!

You are viewing item number: NP3421

What Our Customers Say

Customers Who Bought This Item Also Bought

Denso NP3421 Iridium Long Life Spark Plug - Direct Fit

NP3421 3421


You save $3.98 (15%)

See all pricing

Add to Cart

Copyright ©1995-2015 Auto Parts Warehouse. All Rights Reserved.
Please read Auto Parts Warehouse's Updated Privacy Policy