Denso or NGK sparkplugs

[Old Guy]

The service manual lists the NGK PFR6L-11 and the Denso PK20PR-L11 as replacement plugs for the C23B. It getting around to time for a plug change and some other maintenance and I was going to order some plugs and other stuff from Rock Auto. I had always thought of the Denso and NGK platinum plugs as being equivalent products (I think NGKs are what are in the engine right now). I normally wouldn't obsess about the price of plugs; but, right now the NGKs are listing at close to twice the price of the Denso plugs. This caused some second thoughts.

I don't need these for a bit so I am sitting on the order. Does anybody have any observations that suggest the NGKs warrant the big price discrepancy?

 

[AcuraNSX]

Well, I ordered the Denso ones from summitracing, they had free shipping promo since they drop shipped from Denso, and for the price I couldn't beat it. Yes, the NGK is what I used before, but the Denso are OEM suppliers and the shop manual lists them as an acceptable replacement. I have used Denso in other cars, and NEVER a problem. They make good stuff. I wouldn't be afraid old guy.

 

[Larry Bastanza]

The service manual lists the NGK PFR6L-11 and the Denso PK20PR-L11 as replacement plugs for the C23B.

Dude, You have a 2.3 liter engine??......

Could not resist

 

[Old Guy]

Dude, You have a 2.3 liter engine??......

No; but, apparently some finger coordination issues.

Interesting bit of info I discovered trolling the internet while drinking the morning coffee. The only vehicle in the NGK application list for the PFR6L-11 is the NSX. The Denso PK20PR-L11 cross lists to a much larger list of vehicles. It seems like the PFR6L-11, like the Bridgestone RE010 is an NSX specific application and perhaps comes with an NSX specific price. I expect that sparkplugs don't really age 'in the box'; but, given that the PFR6L-11 only lists for the NSX, you have to be wondering about how long some of them have been sitting on the shelf.

So, looks like the Denso is going to be the pick.

 

[Honcho]

[MENTION=26435]Old Guy[/MENTION] deep in the recesses of my NSX brain, I remember reading something about the difference between the two being that the NGK used a platinum center electrode and a platinum ground electrode, where the Denso only used platinum on one of the electrodes (can't remember which one). Honestly, I think even if that is true, both will work fine.

 

[Old Guy]

@Old Guy deep in the recesses of my NSX brain, I remember reading something about the difference between the two being that the NGK used a platinum center electrode and a platinum ground electrode, where the Denso only used platinum on one of the electrodes (can't remember which one). Honestly, I think even if that is true, both will work fine.

No and yes to the double platinum thing. Both NGK and Denso offer single platinum (just the center electrode) and double platinum (center electrode plus platinum on the ground electrode). However, the Denso and NGK listed for the C32B are both double platinum.

You are correct that when fine wire spark plugs first started coming out, it was just the center electrode that was palladium or later platinum or iridium. The fine center electrode eroded faster which is why they were made from the exotic metals to enhance durability. The double platinum option came later, probably to meet the CARB / EPA requirements to comply with emission requirements for 7 (or whatever the number is) years without maintenance. So, perhaps sometime in the '90s Honda specified double platinum when single platinum was the more common product. I don't know when that extended no maintenance emission compliance requirement was implemented.

The whole palladium / platinum / iridium thing reminds me of the Steve Martin Googlephonic moon-rock needle skit; but, I am dating myself.

 

[ralph cerbone]

NGK or DENSO are fine ,my preference is NGK , lets just not get into the anti- seize discussion ,LOL

 

[The King]

I would pay the little bit extra for the NGK. It's not like you're putting new ones in the NSX every couple years.

 

[Miner]

A couple of years ago I was chasing a misfire on my 02 TL-s, with 245,000 miles at the time. I suspected a coil pack, but figured the amount of effort to pull a suspect plug, find it was bad and then have to go get a replacement was more hassle than changing them all as part of the effort.

All 6 plugs looked very good, would have been good for another 250,000 miles easily.
I ended up changing 1 coil pack, and then a few weeks later another misfire so I changed all the coil packs.

Amazing the quality of a 2002 vintage spark plug, mated to a coil pack (coil on plug), and most importantly, unleaded gasoline, I remember the days when a plug at 20,000 miles looked terrible. Oh, those were the days.

 

[Old Guy]

NGK or DENSO are fine ,my preference is NGK , lets just not get into the anti- seize discussion ,LOL

What is anti-seize :smile:? I do note that when I checked the availability of PFR6L-11 on clubplug.ca they offered me the option to purchase some anti-seize with the plugs. Even though they are an NGK specialist vendor they don't appear to read the NGK technical bulletins.

 

[Old Guy]

I would pay the little bit extra for the NGK. It's not like you're putting new ones in the NSX every couple years.

Perhaps; but, the price difference between the NGK and the Denso gets me close to 65% of the price of a new ignition switch from Rock Auto. I don't need the switch; but, the NSX ignition switch is an orphan that is not cross listed to any other car so availability might become an issue in the future. If there is no quality difference between the NGK and Denso plugs I am more inclined to put the money some place where it might have some value.

 

[The King]

I have been using NGKs for 40 plus years in Hondas, with great results. Guess I'm a creature of habit. Good point about the ignition switch. Is the one from Rock Auto from the same manufacturer as the OEM?

 

[Old Guy]

I take no issue with NGK parts. They have probably been my go-to plug vendor for cars and motorcycles for 30+ years. Although that might be because there don't seem to be many / any local vendors for Denso. If it weren't for the fact that when I scrolled through the list on the Rock Auto website and you see the Denso and the NGK listed pretty much side by side and you see the price discrepancy, this would not have been a question for me. The NGK PFR plug is about twice the price of any other double platinum plug in the Rock Auto listing and is priced about the same as their Iridium plugs.

Standard Motor Products is the listed vendor for the switch I am looking at. Airtex Wells is the other Rock Auto vendor listed for the switch. I suspect that neither of those vendors makes the switch and might source it from Yau Young which is a Taiwanese parts vendor specializing in automotive locks and switches. I have no idea who the original Honda supplier is / was and whether the current Honda stock still comes from that original vendor.

As an observation, the switch is still available from Honda and if you buy it from one of the on-line parts discounters, the Rock Auto price is not a phenomenal savings. What works for me is that the switch ships from the same warehouse as the sparkplugs which means that the incremental shipping cost is a couple of $. That changes the calculation significantly since shipping costs from the US using courier for items less than $100 usually kill the savings associated with buying from a discounter compared to the dealer. If it weren't for the savings associated with doing this at the same time, I probably wouldn't be doing this.

 

[The King]

Thanks Old Guy. A very detailed explanation as usual!:adoration:

 

[ralph cerbone]

I take no issue with NGK parts. They have probably been my go-to plug vendor for cars and motorcycles for 30+ years. Although that might be because there don't seem to be many / any local vendors for Denso. If it weren't for the fact that when I scrolled through the list on the Rock Auto website and you see the Denso and the NGK listed pretty much side by side and you see the price discrepancy, this would not have been a question for me. The NGK PFR plug is about twice the price of any other double platinum plug in the Rock Auto listing and is priced about the same as their Iridium plugs.

Standard Motor Products is the listed vendor for the switch I am looking at. Airtex Wells is the other Rock Auto vendor listed for the switch. I suspect that neither of those vendors makes the switch and might source it from Yau Young which is a Taiwanese parts vendor specializing in automotive locks and switches. I have no idea who the original Honda supplier is / was and whether the current Honda stock still comes from that original vendor.

As an observation, the switch is still available from Honda and if you buy it from one of the on-line parts discounters, the Rock Auto price is not a phenomenal savings. What works for me is that the switch ships from the same warehouse as the sparkplugs which means that the incremental shipping cost is a couple of $. That changes the calculation significantly since shipping costs from the US using courier for items less than $100 usually kill the savings associated with buying from a discounter compared to the dealer. If it weren't for the savings associated with doing this at the same time, I probably wouldn't be doing this.

I have a new switch that I got from Tim P , marked made in Japan , stay with OEM

 

[nis350]

what is the price difference between oem and aftermarket switch? does the aftermarket ones fit/work perfectly?

Perhaps; but, the price difference between the NGK and the Denso gets me close to 65% of the price of a new ignition switch from Rock Auto. I don't need the switch; but, the NSX ignition switch is an orphan that is not cross listed to any other car so availability might become an issue in the future. If there is no quality difference between the NGK and Denso plugs I am more inclined to put the money some place where it might have some value.

 

[Old Guy]

You can get it from Rock Auto for around $42 US$. The OEM switch lists for about $74 US$; but, the discounters sell for about $54. Check around because a couple of the OEM vendors listed it as discontinued. As I noted, the price difference is small. The big saving for me is the shipping cost saving.

Can't comment on fit since I am purchasing as a spare part and don't plan to install it until I need to.