2005 Honda Civic - NGK Iridium or Denso Iridium Lo

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NGK Laser Platinum Spark Plug S(PZFR6F-11)

Denso SKJ20CR-A8 Iridium Long Life Spark Plug

For another 100,000 miles?

Any reason to chose one over the other?
 
Both are oem/oes recommended plugs. Negligible performance difference or life difference. Whichever is less expensive. Also see if ngk iridium ix are available. They are preforming excellent in my Acura atm. Civic has Bosch iridiums , sort of as an experiment since everyone says don't use Bosch in an Asian vehicle. So far no difference in performance or mileage.
 
What came OEM? IIRC Denso plugs were OEM on our Fit. I'll throw another set of those Densos at it in 30k miles when it hits 80k miles. No complaints about their OEM plugs, since they work fine.
 
The platinum plugs are good for 100,000 miles.

The Iridium can go quite a bit longer than that.

I'd figure out what the car came with and stick with that.

On my Taurus after 98,000 miles the plugs looked pretty good. However, the rest of the ignition system needed to be replaced. The Solenoid pack and wires looked pretty bad and I imagine that it was the Solenoid that had given up the ghost. However, I decided to replace the plugs.

Just something to think about.
 
I'm running IR Fusion in my 06. 100k (km) still running great. Slight increase in throttle response, mileage is a wash.
 
This particular one came with NGK's but the two plugs listed in the OM/SM are:

NGK: PZFR6F-11
Denso: PKJ20CR-M11

The NGK Iridium Ix Spark Plug (ZFR6FIX-11) is available as well but was under impression that the ground electrode on those is not Iridium.

The NGK's are cheaper but it isn't a huge issue. It is normal maintenance no issues with the car or the rest of the ignition system.
 
OEM plug is a double platinum plug. Question here is do you want to put double platinums back in or replace them with Iridiums ?

If double platinum then stick to NGK oem plug.
If Iridium , then I highly recommend NGK IX series #ZFR6FIX-11, with Denso #SKJ20CR-A8 being a close second recommendation.

Here are the links to the home pages of both plugs :
NGK Iridium IX
Denso Iridium Long Life
 
Although either NGK or Denso can be installed at the factory, I have always liked to run NGK in a Honda and Denso in a Toyota. There are hundreds of horror stories on the net about Bosch plus in Japanese engines, but I have run the standard Bosch Platinum in my 1991 Honda CRX without issue. What seems to be the culprit is the Bosch multi-prong grounded plugs like the +2 and +4 causing misfires. Oddly, my CRX came equipped from the factory with Champion plugs and it never skipped a beat. I now use NGK G-Power Platinums in it.
 
I ran Bosch plugs for 50k in my Integra GS-R and in my S2000. Not a single misfire code or anything like that. Total hogwash that Bosch doesn't work in Japanese motors.
 
You want to use the Denso LL or the NGK Laser Plats/Iridiums for long life operation. They have a platinum ground strap for minimal erosion. The NGK Iridium IX is NOT a long life spark plug since it does not have a plat ground strap. I had them for 40K in my Toyota Tundra V8 and the ground electrode started to erode.

I have Denso LL's in my 02 Chevy Silverado 5.3L, replacing the OE double plats @ 92K. And yes it runs fine despite people saying it need murrrican* spark plugs.

*ACDelco, Champ, Autolite.
 
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Well, had to order them by 4:59 to use the discount code.

Guess we will how the Iridium does, I can always stick a set of the Honda ones in it if I don't like anything about them.
 
If both plug model are OEM, then they have tested it when designing the engine / car and have told both companies to adjust / fix any problem found, and therefore should perform close enough and either should work.

Other brands may also work, but since it is only tested by the plug manufacturer and not the car manufacturer, you'll never know how much of a difference (if any) it is making.
 
Originally Posted By: dparm
I ran Bosch plugs for 50k in my Integra GS-R and in my S2000. Not a single misfire code or anything like that. Total hogwash that Bosch doesn't work in Japanese motors.


Exactly, this is internetz rumor mill nonsense.

Now granted it is true that GENERALLY you should stick with the same number of ground tips that came with your car. However in many cases even this is not an issue, as I know of MANY models that have identical engines in a number of markets yet each market will specify different plugs with a different number of ground tips.

ACTUALLY THE MOST CRITICAL SPARK PLUG SPECS ARE

1) Thread pitch
2) Length of plug in combustion chamber
3) Heat range

The others are less critical

4) Number of ground tips
6) Electrode metal and or design
5) type of metal


I think NGK has a vast viral marketing arm that flood DIY sites like this and push NGK with various claims, all of which are dubious at best.
 
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I ended up ordering the Denso SKJ20CR-A8 Iridium Long Life since no one had anything bad to say and I wanted to try something different.

NGK and Denso were the only ones ever under consideration.
 
Originally Posted By: antiqueshell
Denso tends to be the OEM "preference" for Honda, and Toyota, with NGK being a secondary option.



My Acura and Honda both had NGKs.
 
Originally Posted By: dparm
Originally Posted By: antiqueshell
Denso tends to be the OEM "preference" for Honda, and Toyota, with NGK being a secondary option.



My Acura and Honda both had NGKs.


Same. Even though Denso is supposedly OE for our cars, both had NGK double platinums from the factory.
 
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