The Truth About Spark Plugs....

since OEM is half NGK and half Denso, if one were to replace with only one or the other... which is better?

 

It's not that simple. You actually need to keep using both makes of plugs, but it is critical to alternate the sides you use them on every 30k miles so you don't melt the heads!

 

cool. what brand of blinker fluid so you recommend?

 

Purple Helmet.

 

Lol. Doesn't matter if you use Densos or NGKs. I usually just go Densos from the dealer when I'm getting OEM oil filters too.

 

thanks. just wondering if there were any general preferences or pro's/cons thoughts out there

 

I changed my plugs w/ Denso Part#

$8 90919-01192 Toyota Genuine Spark Plug

90919-01192

$18 K16TR11 Spark Plugs, Pack of 4

K16TR11's, NGK plug wires Part#

$38 RC-TE66 Spark Plug Wire Set

RC-TE66 and a Toyota OEM fuel filter Part#23300-62030. All parts for my 3.4 V6. My truck ran better before I changed everything. It runs fine plenty of throttle response, no missing. In park it idles just fine too. But in drive at stoplights it idles at about 600 rpms and is really rough and the dash and seats shake. I cleaned the MAF, Throttle body and IAC Valve. My truck did not run like this at all before I changed those parts. I checked all the spark plugs for cracks , gap specs, etc. Checked wire connections too. All 3 coil packs look just fine. I even took it in for a compression test and it passed w/ flying colors since I do have 252,000 miles on the engine. The time before I did a tune up, I only changed the plugs, belts and fuel filter. Left the wires alone. Don't know what to do next.

 

If I may, everyone has they're own experiences and opinions, mine it that i run regular ngk plugs in everything, champion in yard tools cause thats what hd has. My personal reason is the shop I worked at a bike didn't spark, the customer supplied the appropriate Bosch plugs cause that's what he really wanted, no spark from them, completely regular nothing special ngk plugs went in and there's nice blue sparks. Looks who's bike is running nicely. I will say that there are rare occasions that the iradium plugs are needed but that's very rare and for stuff like Aprilias.

 

Interesting read, thanks for the knowledge

 

Lmao..... This guy..... Jajajaja. He's got some classics earlier in the thread too. I don't have it in me to yank the noobs chains like he does, but I do laugh at it... Hahaha

 

This ever clear itself up? Was thinking it might just be the EFI system remapping fuel teams, etc.

 

It only does it under load. Not in neutral or park. My buddy seems to think it's the motor mounts since they are worn out and the rear transmission mount is just as bad. It's not crazy shaking it's just annoying. I just don't know if I want to change all 3 mounts

 

Wow. I didn't even know this was still out there anywhere and was actually looking to see if it was since I wrote it so long ago. I wrote "The truth about spark plugs" long ago, back in maybe '98, '99 or 2000, somewhere in there, and originally posted it on Themestream, and after they went under I reposted on Epinions as well as on my own website. I lost the writeup some time ago and was doing a search to see if there was any record of it anywhere, which brought me here. Hope the information was at least semi-useful to some of you.

@chris4x4, you're absolutely right, I neglected to include any mention about the path of least resistance. Chock it up I guess to the fact that when I wrote that I was a much younger tech, and less experienced writer, and now that I've found the article again I'm planning to do a re-write to include a bit of additional information and some observations that probably should have been included in the original version anyhow. Thanks again for the fact that you had read it, and posted it, or I'd have never found it again I think. Take care.

 

Keep in mind that some Toyota vehicles spec a Iridium plug that has a 80,000 to 120,000 mile interval. If you have an engine that specs Iridium you need to stick with it. You don't want to go from Iridium to a plug that is not Iridium. In the alternate if you have an engine that specs a plug that is not Iridium you can change to Iridium. The main reason to change to the Iridium will be longer intervals between changes. You will get better efficiency over a longer interval. I have had excellent service from both NGK and Denso plugs over the years.

The minimum specs are 30,000 miles on the basic plugs. You can go longer but you will lose efficiency. Your emissions may increase over time which may lead to problems. Some of these motors have tight emission controls that can foul like the air pump. Your goal should be to make the engine run as efficient as possible for the longest interval.

Anytime you open the motor you increase the the possibility of introducing silicon or any type of damaging contamination. Frequent plug changes, oil changes, and air filter changes are examples that may introduce the likelihood of contamination in the motor. An example would be plug changes on a dirty motor. If you pull the plugs and knock dirt into the combustion chamber the dirt may damage cylinders, pistons and bearings. The same can happen with oil changes and air filter changes or opening the air box. Again, the frequency of intervals increases the likelihood of damage.

It can be lots of fun working on your vehicle. You can also make huge mistakes that cause many problems. Do your research and take your time.

 

I think you're mostly right about that, however, not in every case. Certainly for the average person there can be no argument that going from Iridium to something,..less, is not great advice, but for somebody with a specialty vehicle, street strip, track, heavy off road, that runs their engines under more demanding conditions or using performance modifications may be very much inclined to make changes to plugs and filters on a lot shorter interval than John Doe owner whose driving mostly includes city or freeway miles with an occasional mud hole or hill climb thrown in.

If you ARE somebody that meets that "other" criteria, and have a more frequent maintenance schedule, there's absolutely no reason why you should use iridium plugs. The ONLY advantage of using them is longevity. If you change plugs more frequently then a platinum or double platinum, or if it's a strip vehicle that might even see frequent teardown, plain copper, is perfectly fine. There is no reason to waste money on an expensive plug if you don't plan to keep it in the engine long enough for it to have value. And as far as contaminants are concerned, that's what shop air and long reach air nozzles are for. Do a good job of blowing around the plug area and there is little or at least greatly reduced chance of anything unwanted finding it's way into the cylinder.

For the record, I wrote that article long before Iridium plugs were widely available to the general public, so that is why there was no mention of them in the article. I will certainly include some information regarding them in the re-write whenever I get around to doing it. Thanks again for the original mention and thread.

 

Can anyone direct me what size Denso Iridium plugs I can use on my 2014 Tacoma PreRunner? Im on Amazon trying to purchase a pack of 6, and Amazon says it does not fit my truck.

 

https://www.sparkplugs.com/Automotive-l134.aspx

 

Thanks man! Im on it!

 

Hey all.. 2010 Taco 6cyl 4x4 here.. I just hit 101k and due to kids/ life/slacking Ive been slacking on maintenance except oil changes. Looking to change my plugs for the first time and was wondering if these denso platinums were good? 3 dollars each seems like a really good deal, but was hoping for expert opinion before installing anything. Also, considering how stupid ive been in not changing the plugs out a long time ago, is there anything i should do to avoid major problems getting the old ones out?

6 pcs Denso Platinum TT Spark Plugs 2005-2015 Toyota Tacoma 4.0L V6 https://www.amazon.com/dp/B01MYAWYSD/ref=cm_sw_r_cp_apa_i_DGi7AbN9QQ73V

 

they will probably be fine, but I know that the v6 engines run a lot better using the standard copper DENSO or NGK plugs probably cheaper cost too,