Denso (5304) IK20 Iridium Spark Plug, Pack of 1

by Denso

Product Features

• Low fuel consumption
• Excellent acceleration and performance
• Stable combustion during idling
• Long life and high reliability
• Features iridium with high melting point

Product Details

• Shipping Weight: 1.6 ounces (View shipping rates and policies)
• Shipping: Currently, item can be shipped only within the U.S. and to APO/FPO addresses. For APO/FPO shipments, please check with the manufacturer regarding warranty and support issues.
• ASIN: B000M6UR82
• Item model number: 5304
• Average Customer Review: 4.3 out of 5 stars  See all reviews (32 customer reviews)
• Amazon Best Sellers Rank: #518 in Automotive (See Top 100 in Automotive)
  • #2 in Automotive > Replacement Parts > Ignition Parts > Spark Plugs & Wires > Spark Plugs
  • #2 in Automotive > Performance Parts & Accessories > Ignition & Electrical > Spark Plugs & Wires > Spark Plugs

Product Description

Denso Iridium Spark Plugs are designed to ignite the air-fuel mixture in the engine cylinder by generating sparks between the center electrode and earth electrode. They employ an iridium alloy for the center electrodes and provide superb ignition performance. These plugs have lower fuel consumption and higher acceleration performance as well as stable combustion during idling, which contribute to the cleaner exhaust.

Customer Reviews

Most Helpful Customer Reviews

33 of 34 people found the following review helpful:

5.0 out of 5 stars Excellent, May 31, 2009

By 

Robert Petkus (New York) - See all my reviews
(VINE VOICE)    (REAL NAME)   

Amazon Verified Purchase

This review is from: Denso (5304) IK20 Iridium Spark Plug, Pack of 1 (Misc.)

Picked up a set of these to replace the stock NKGs on my 2005 Honda Accord 4 cylinder after 97k miles. The originals were still good -- just doing a spring-time overhaul.

Engine felt smoother although that could be psychological. What is real, however, is a solid and consistent 2 MPG increase in fuel economy from what I was averaging over the last 60k miles.

I'll try to update this review after 30k miles or so.

23 of 23 people found the following review helpful:

5.0 out of 5 stars smooth running engine with this Iridium spark plug, June 2, 2009

By 

Edison "hightech lover" (United States) - See all my reviews

This review is from: Denso (5304) IK20 Iridium Spark Plug, Pack of 1 (Misc.)

This fits in 1999-2003 Toyota Sienna. Trick to replace the three spark plugs in the back is to remove the windsheld wipers and the plastic piece for intake air and rain water collector -- a big piece from left to right.

After the spark plugs replaced, the engine runs smooth, starts faster. Since Iridium is very expensive, the tip is little -- 0.4mm in size, so that it can spark easily. Denso's web site says it has life 60,000 miles. Denso also developed one for Toyota and Lexus that has 0.7mm tip, that one can last 120,000 miles. 0.4mm has more precise ignition time, so that better fuel econemy.

Until recently, platinum was considered the best material to use on the top of an electrode because of its durability. However, Iridium is 6 times harder, 8 times stronger, and has a melting point 1200 degrees higher than platinum. Put that into a harsh environment such as an engine piston chamber, and you have a spark plug that can resist wear much better than platinum.

10 of 10 people found the following review helpful:

5.0 out of 5 stars Faster Starts, January 20, 2010

By 

Wayne Bengston (Cordelia, CA) - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Denso (5304) IK20 Iridium Spark Plug, Pack of 1 (Misc.)

I just installed a set of these in my 2001 GL1800. I previously had NGK standard plugs with under 1,000 miles on them and AC Rapidfire plugs with 24,000 miles on them.

The AC Rapidfire plugs were my previous favorite, but it seems they are not the same plug anymore, having lost the serrated center electrode. The Rapidfires I had previously installed were the non-serrated type. They still provided faster starts than new NGK plugs, but not the improvement I had witnessed in other engines with the serrated Rapidfires.

The IK20s, which, in spite of the title and picture, are Iridium Power plugs, provided about a 1/2 second start time, where new NGKs gave a slightly longer than one second start, and the Rapidfires gave a slightly less than one second start. The engine is running smoother than with the 24,000 mile Rapidfires, but that is no suprise. I can't tell if it is running smoother than with new Rapidfires, as the difference is negligable. That is the extent of my review so far, as I have not yet collected enough data to see if I get a fuel economy change, and the power difference is too negligable for me to tell.

The Iridium Power spark plug is good for 30,000 miles as per the Denso FAQ. If a 5% fuel economy gain is achieved, then the plugs will pay for themselves a couple of times in that time.

There is also a Denso Iridium Tough plug available, the VK20, which is supposed to give less of the benefits of the Iridium power, but last 60,000 miles while still giving improvements over conventional plugs.