Why two brands of plugs

I have a 2011 Tacoma 4 L V6 just over 200,000 miles. I have never change the plugs finally decided to do so, to my surprise Toyota used two different brands and NGK and Denso, this was strange. Why would they do that? these are the original plugs that came from the factory, I replaced them with NGK iridium plugs.

 

They do this to keep both suppliers happy. That way if one can't deliver they have a backup supplier.

 

Wow ok thanks for that, I guess that’s a way to keep them in their pocket, but it confused the heck out of me.

 

A more interesting question is why did you wait 200k for this basic maintenance?

And IIRC only the 2.7 specs irradium plugs.

 

Congratulations on the length of time to replace plugs. Was the truck running okay before you changed them? Any noticeable differences since changing?

 

Never had a problem contacted a Toyota mechanic neighbor that told me he has changed plugs that are over 300K and when I did the plugs not to worry about the coils cause they are good to 500K
What do you mean by “IIRC only the 2.7 specs iridium plugs”

 

Never had a problem always ran and started. Good, plugs have been in for a week. Still starts really good response. Well I haven’t done any mileage test done it yet and see if there’s any major improvement but it’s a new set of plugs.

 

If I Recall Correctly the 2.7 4 cyl specifies iradium plugs, not your 4.0 V6

Most folks put in a full set of NGKs just like what you took out.

 

Do not use iridium plugs on a 4.0 v6

 

200k on stock plugs damm!

 

Why not?

 

I was surprised when I saw that too. The Denso looked better when I took them out. I went with Denso.

 

As long as you don’t buy champion you’ll be fine.

 

What did the tips of those plugs look like?!?!?! Those gaps had to be HUGE at 200k miles on stock plugs.

 

I can’t talk about the technical issues but I installed iridium plugs in my 6 cylinder and it ran like crap. I immediately yanked them and installed the regular plugs and it ran great. Just don’t use iridium.

 

Interesting. I’ve only used the original non iridium spark plugs myself but there many others using iridium plugs on the 1GR-FE without issues.

 

The replacement frequency on the V6 (every 30k miles) makes iridiums a waste of money. Spark is spark; just because one metal sounds fancier doesn't mean it sparks better.

 

Pretty much. Parts availability and money.
I did a little research on it a few years ago.

https://www.tacomaworld.com/threads/2015-taco-spark-plug-confusion.674162/page-4#post-23749085

 

I would hope that anyone using those would increase the replacement intervals to at least 100k otherwise why switch.