The NGK plug finder that Mike gave a link to above shows an “OE laser iridium” plug. OE = original equipmemt. Which means that’s the exact plug they sell to Mazda.
NGK #ILTR6B11
Which is the exact plug that the OP bought in the first place. This is not rocket science. Regap the plugs to Mazda specs and put 'em in.
No we have the question cleared up of what the exact plug this engine calls for. You can buy those plugs from NGK for $8.48 each plus shipping. So the dealer price from Mazda is pretty good. That plug will be the EXACT PLUG you buy from Mazda.
But - THE GAP STILL SHOULD BE CHECKED.
Mike - You may be right but I have the SkyActiv engine which is very high compression and still very new (2012 and newer). In time I am sure there will be a cross reference or the auto store will start to carry them. I put about 40,000 miles a year on my cars so I hope that I will be able to get one from Advance Auto or Autozone by the time I have to change them.
I will be able to get one from Advance Auto or Autozone
The Advance Auto and Autozone near me while they do carry NGK…they don’t carry their full line. Only certain vehicles. I have a good local parts store near me that carries the full line of NGK plugs. If NGK makes it - they’ll have a listing for it and probably have it in stock.
If I use the gappping tool posted by BustedKnuckles to widen the gap to 0.54, can i use the same gapping tool to measure it afterwards?
would touching the center tip with metal damaging it?
or do I need something like a feeler gauge… how brittle is the center tip? I can use a regular 0.99 metal gauge to measure the gap as long as I don’t apply any force on it correct?
The wire gauge is much better than a feeler gauge. Just don’t try to force the wire in. It should slip easily, if there is any resistance at all, pull back and use the next smaller wire. Rest the wire on the anode and slid it down under the tip, but be careful, if the spark plug has a platinum pad on the anode, then you just have to be very careful.
Try using the wire closest to the thinest end of the gap range and open the gap so that this wire slips in with a little room to spare. That should put you in mid range. Don’t get too anal about the gap, it works over a very wide range. Close counts in hand grenades, horseshoes and spark plug gaps.
ok I just tested the MPG on my car, i get 250m/11= 22.7MPG with about 70% highway driving, mazda 6 V6 is rated 17/20/25. I think it’s running pretty decent. car runs silky smooth. I put mobile synthetic oil always.
I doubt I will see any improvement putting new plugs in for $240, can i monitor mpg and change plugs when it gets worse? would the plug be stuck in there and can’t get it out? that seem to be the only downside of waitign?
So the car is rated 17 city, 20 combined, 25 highway
And you’re getting 22.7 combined
Sounds like you’re in the ballpark at the moment
I’d return the plugs and get the Mazda plugs at the dealer’s part department.
It is possible that the NGK listing is in error, and for the extra few bucks it’s worth making sure the plugs are right. You can still install them yourself.
The “damage” advisory for iridium plugs is because the iridium center electrode is relatively brittle and of a much smaller diameter and can be damaged. Irridium is superior, as it’s less subject to erosion, being a harder metal, but in this case I’d stop by the Mazda part counter and get am OEM replacement.
One dealer sales told me the factory IEN plug is platinum (which is not as good as the iridium I have)
Also, is the OEM spark plugs installed with anti-seize? so I have no problem removing them if I leave them in for a while if I don’t change them right now?
I don’t know what you mean Platinum - Not as good as iridium. Iridium plugs just last longer - PERIOD. I wouldn’t say one is better then the other.
If you buy NGK plugs then you don’t need anti-seize.
iridium is preferred because it’s a pain to change the plugs on this car.
my question is does the spark plug came with the car initially have anti-seize applied when the car is brand new? so I don’ t need to worry about not being able to remove it if I keep it in there for a while.
iridium is preferred because it's a pain to change the plugs on this car.
That is a very valid reason. Same with my wifes Lexus. The back 3 plugs are a royal pain. Took me over an hour to replace. - less then 15 minutes for the front 3.
OK, I finally decided to replace the plugs, just did the three front since it’s easy to get to 
the old plugs don’t look bad at all at 127k miles…however I test drove it and I can notice more pickup right away and the car is a little more enjoyable to drive as a result.
now the bad news, being the amatuer I am, I broke the red latch when I pull it out too much (circled in green)
also because I just pulled the cap hard, the metal piece that fit into the plastic tube (circled in red) is also not fitting in there any more…
however everything still seem snug and no wire is touching the hot engine… do I need to worry about these two things (the two circles)??
the spark plug gap seem noticably bigger than the OEM I got from mazda I don’t have a guage to measure it though since the OEM plugs I got from dealer is pregapped I didn’t bother get a guage.
anyway the car runs great i’m just worried i might have messed something up by pulling too hard on the cap (on top of the spark plug) without removing it first through the red colored latch…
The red latch is just a lock for the connector release. I would not worry about it. The other plastic tube is a wire loom holder to keep the wires from bouncing around. You probably either broke it or wallowed it out of shape. As long as the wires stay clear of anything hot, it should be Ok. The spark gap in the old plugs are probably much greater than new, with 124, 000 miles on them. The spark plugs lose a bit of material as they wear. That’s why they need periodic replacement. Now, you need to get to those back plugs.
the spark plug gap seem noticably bigger than the OEM I got from mazda I don't have a guage to measure it though since the OEM plugs I got from dealer is pregapped I didn't bother get a guage.
I haven’t bought a plug in the past 20 years that wasn’t pre-gapped. And I ALWAYS check the gap. And I still find plugs gap out of spec every now and then. You should ALWAYS check the gap.
I plan to do the rear 3 this weekend… hope i don’t break something else.
do I need to order a manifold intake gasket from dealer before I begin? or can I reuse what’s in it?
I didn’t measure the gap, but I did visually exam all six new plugs, they seem about the same gap…
The OEM plug from dealer is is motocraft platinum plugs rather than the NGK iridium which I bought then returned.
Just an FYI, the plastic “catch” that you broke (circled in green) often breaks. The trick to not breaking them is to push the plug in fully before pressing the release, and then (while still holding the release compressed) pulling the connector out. The clips and their corresponding surfaces have backward “catches” on them, and if you don’t push them in fully they won’t release cleanly… they’ll break. The connector fortunately has plenty of friction to hold itself together even without the “catch”, so you’ll have no problems. I have one, maybe two, broken clips on my own car.
I think it’s great that you’re doing your own work. I will suggest, however, that you begin to stock up on the necessary tools to do the job properly. If you pick up a repair manual, processes described in there will list the tools you need, and you can get them before you begun the repair. Tools and test/inspection equipment are an excellent investment, not an expense. They’ll pay for themselves many, many times over. They’ll almost always pay for themselves the first time you use them.
thanks for the tip, which part is the ‘release’? the red piece? I sill need to pull the red latch all the way back first before your steps correct? would it hurt to spray some wd-40 on them?
also do I need to get intake manifold gasket from dealer before attempt the back 3 plugs?
yeah it’s a lot of fun working on the car especially when it runs better afterwords!