Denso Iridium TT Spark Plugs-Get Some!

Just go buy some, put them in and slap yo self and say, "Thank you, J.R. for this tip." Here's why.

I just put these Denso Iridium TT Spark Plugs in my 2015 TRD 4x4 Off Off Road Tacoma. Now mine is a base model, so it didn't come with iridium plugs installed. I was given a certificate by my service manager where I could extend my warranty by 5 or 10K miles, I can't remember which one it was, as long as I purchased the extension before I hit 25K miles. Cost will be $299 and with that, they would put in a set of iridium plugs. He said that extension would pay for the cost of the plugs and installation which is priced at around $300. I thought they all came with them, but he said the base model, like mine, comes with regular plugs. And they will need replacing at 30K miles.

Now, like most of you are thinking, $300 is a lot for a spark plug change. I do my own maintenance and I knew I could just pick up a set for around $40-50 bucks. Iridium plugs are expensive and normally cost between $6-9 a plug. My set was $41 with tax and all from Advance Auto.

Now since I have the Off Road 4x4 model, my gear ratio is 4.56. I think the Sport model has 4.11 gears in it. So I knew I would be getting the lower end of the 16-22mpg average that was rated on my truck. And I did. I have 7K miles on it and I check my gas mileage weekly. I have never gotten over 16.8mpg. Ever! I average 15.9 to 16.1, so the real average is 16mpg. The one time I got 16.8 was a short 100 mile trip, down hill all the way, no wind, all on the highway, lol. And I don't drive 55! I am a travel nurse and I drive 75-80 all day long. I go to a place and stay for 3 months and then move on. So I put a lot of miles between locations, but not much driving while I'm there. Still, I average 16mpg. Go figure.

But today!!!!! I put the new plugs in, filled up the tank and took a trip. I drove about 95 miles on the interstate, with the last 20 miles in the city with constant stop and go traffic. It was a great test of mileage. Plus the winds were steady at 15mph with frequent gusts up near 30mph. I was blown all over the interstate. So I figured my mileage would probably be the same today, with the wind conditions.

But my little red Taco got 18.6 mpg! I was stoked!!!!! I can't wait to test it with no winds blowing me all over the place. Dare I think to get 19 mpg??? It will be interesting.

But here is the part number for the 4L V6. Denso Iridium TT Plugs

$8 IKH20TT Iridium TT Spark Plug, (Pack of 1)

IKH20TT 4704. Get them at Advance Auto or anywhere they sell them. You will not be disappointed!

The TT stands for Twin Tips. Look them up and you will see what that means. They use a very small 0.4mm center iridium electrode tip and the ground strap has a 0.7mm platinum tip on it. It makes a very hot spark. I've never seen a gas mileage increase like that with any mod I've ever done. Ever!

18.6 mpg! I would not have believed it if I hadn't seen it myself. For once, a product delivers like it says. The plugs that came in my truck were the

$6 NGK LFR6C-11 V-Power Spark Plug, Pack of 1

NGK LFR6C-11 7787 plugs. They are made with copper and nickel. Gapped at 0.43. The Denso plugs are gapped the same. Don't drop them! You will have to use a tool to bend these as you will not want to put a gage in there and bend them up due to the small tips in there. But they come pre gapped at 0.43 so you will be good.

Best of luck!

 

You don't have 4:56 gears unless you upgraded them yourself

6 lug v6's = 3.73

6 lug i4's = 4.10

 

Yeah, that's what I though too, before today. I check my gas mileage every week and daily during trips between nursing assignments. I got 18.6 mpg today on a 115 mile trip. That's a 2.6 increase that is real. I have no idea what others will get, but this is what I got.

 

No, I have 4.56. I looked it up too and confirmed it with the Toyota service department. 7.5" diff, 2 pinion limited slip. The code is A04C. 4.56 gears.

 

I agree 100% my mpg went up about 1.5 mpg with plugs and synthetic gear oil and than I put 32s on it....
But I always say when you do maintenance upgrade your parts, win win........

 

You know what, you may be correct on the 2nd generation gear ratios. I've not done enough investigating to find out, short of pulling off the diff cover and counting the gears for myself. But the old codes that you say are only for gen 1 models, are still found on gen 2 models. So I guess they just put on the codes and said, what the heck, just slam a 3.73 in there and call it a day. That sounds legit. But I was raised in a garage from a little tike to spending over 12 years in the Air Force getting certified as a 7-level master mechanic. Lead technician and all that jazz. Rebuilt a couple of engines in my day, ripped apart many a transmission and gear box, but who am I? And I'm well aware of the claims of many parts makers that theirs is better than this or that. Sure my new plugs are 100K mile rated and I was happy for that. But one little by-product was a 2.6 mpg increase in my mileage and you guys think I'm crazy. Post all kinds of cliche's and a quote here and there. Pissing on my parade. I bet it's just rosey in your house and your kids and wife love to see you come cranking through the door. Scoff if you will, but I also have 3 degrees and know how to work a calculator to figure out gas mileage. If I hadn't seen it for myself, I would have just watched netflix instead of posting my findings, like everyone else does on here. So have a happy night and GFY.

 

Thank you. Finally a positive response.

 

JR
Everyone in this thread was just trying to give you the best possible info that they know is true. Congrats on the plugs. I did it as well with my Tacoma. If you get better performance awesome. Great for you. Please take a little advice. Do a little bit of reading up and verify your statements. Because what you are claiming at least around gear ratios just seems very unique. Almost Custom. Not trying to insult. Just help.

 

Yeah that's the problem here, you try to help people and all the nay sayers come out and tell you that your wrong...
Well I change my plugs every couple years, run full synthetic fluids, change my oil every 3000-4000 miles and flushed my trans twice already...
Factory maintenance schedules are the min not the maximum term....
You can't do too much maint or put too good of parts in......
When you pull you plugs and see the black on the out side, that is the lost energy on the outside of the plug and it's time for new plugs..
It will still run, it will just run better with new plugs...

Iridium plugs are the cheapest performance mod available for the Tacoma and you have to change your plugs anyway....
Thanks for the info....

 

For quoting all those high end mechanical skill sets, you're missing some common sense. Pulling the cover and counting teeth is not needed, and any good mechanic or junkyard picker knows that. Heres a little tutorial for you. http://www.geeksoncars.com/how_7284384_figure-differential-gear-ratio.html

So the dealer told you they needed to be changed in 30k because? They just wanted another $300 for $40 of parts?

It's positive because it agrees with you. And you'll note he did more than plugs.

In my little SCCA car, unboosted, standard copper plugs worked just as well @ $2/per. There was no reason to quadruple the price for the iridium. Performance wise. Of course they were easy to access, so there was no particular longevity advantage. I will say it was a 7500 RPM rev limiter motor, so any plug issue was not hard to spot.

If I read your post right, you based your MPG on a bit over 100 miles of driving? Sorry, not meaningful. Even a full tank is suspect. Run 3-4 tanks and average them and you'll be much more accurate. I truly hope for your sake the MPG has risen. And don't forget it's time that winter blends are ending and summer blends are coming in (reason for current price bump) so everyone will be gaining some MPG.

And yes, my wife and kids love seeing me.

 

Does anyone know why TRD puts iridium plugs in the TRD s/c kit? Is it because of a change in the combustion chamber dynamics or is it just so that you don't have to take off the supercharger? I'm guessing number 2 but you never know

 

"The Law of Small Numbers" - The tendency for an initial segment of data to show some bias that drops out later...

 

Rattlejay65 was indeed wrong.

I put in iridium plugs and noticed no gains in performance or mileage. Before the change, I averaged 16.0 mpg over 142 fillups. After the change, I averaged 15.5 mpg over 91 fillups. The only reason I put in iridiums is so I don't have to touch them again for 100k.

 

Well I did.........
and they run better.......
maybe you need to tighten up your plug gap....

I run them in every vehicle I own and always notice a slight improvement...
But you can't run the gap too big.....
And they don't really last that much longer....
But an old iridium plug is still runs better than most std plugs....