I've tried various types of plugs over the years in different engines with less than satisfactory results. So I wasn't exactly optimistic about trying the NGK Iridium plugs in my stock aspirated V-6 2004 Tacoma with OEM NGK plugs, but I tried them anyway.
Cost me about $44., and took me 1 hour to change them out. For the first time I was actually satisfied with the results. It's a very subtle difference to be sure, but I could tell they made the engine run smoother and with better throttle response.
They cost about 4 times more than OEM, but they will last 4 times longer and give better overall performance results. I definitely recommend these plugs and give them 2 thumbs up.
I wonder if you would have seen the same results from a new set of stock plugs or Platinum Plugs as you are comparing your results with the old plug performance. Like you, I've tried a variety of plugs over the years and I keep coming back to Bosch or Champion Platinum depending on cost. Always remember to use anti- seize compound when installing long life plugs. It will save a lot of frustration years down the road when it is time to remove them!
Drivers tend to fool themselves into believing more expensive items are better: they tend to "feel superior performance" when it isn't happening. The only way to know for sure is double-blind tests where the driver does not know which spark plugs are in the vehicle, or using expensive lab equipment.
The engine had 11,000 miles on at the time of changing the plugs. I saw no appreciable difference in performance over that time. All the old plugs with the 2 electrode design were in very good condition when I pulled them.
While I didn't try the Platinum ones, the Iridium ones did give me results I was very satisfied with.
I did use anti-seize compound.
Desertphile wrote:
items are better: they tend to "feel superior performance" when it isn't happening. The only way to know for sure is double-blind tests where the driver does not know which spark plugs are in the vehicle, or using expensive lab equipment. <
I bought the Iridium plugs about 6 months before installing them.
About a week before installing them I was watching some hot rod tv show where they were testing OEM vs, Iridium spark plugs in a performance engine with various lab test equipment. The results showed not only a 4 horsepower gain (in a 350hp engine though), but also a very slight (.07%) increase in fuel economy. They then showed the difference in spark the two plugs make...the Iridium plug was much brighter and had a much thicker spark than the OEM plugs. But the good thing I found out is; whether the engine is normally aspirated or performance, these plugs will work equally well.
Like I said before, I was a skeptic, but I'm absolutely sold on the superiority of Iridium plugs. I'm just passing my personal experience to others who want the best for their trucks.
I couldn't find the particular video I seen, which was just an engine in a testing facility with lots of testing equipment. But there's a few others at YouTube expounding on the virtues of Iridium plugs.
Not a Toyota truck, but the results are are going to be near the same in almost any engine.
Harley Davidson motorcycle dyno test.
1 day old Stock plugs = 92.5 horsepower. New NGK Iridium plugs = 95.7 horsepower.
3 horsepower gain in the 60 seconds of time it takes to change them in the Harley.
My experience with Bosch Platinums over the years has been less than satisfactory. Lots of compression seal problems and resulting misfires.
NipponDenso Platinums are the Cat's Ass for Toyotas. NGK Plats are pretty good too. Dual Plat is only "required" for waste spark systems (double ended coils), which Toyota has pretty well gotten away from (if not totally)
I put Iridiums in my Chrysler PT Cruiser - and a couple months later I developed a #1 misfire at idle.. I ruled out plug wires and coils by switching them, and figured I'd switch plugs between #1 and #4 to see if the misfire followed the plug.
Misfire went away.
It appears ONE of the plugs wasn't happy firing "backwards".
That's the only experience I've had with Iridium or "fine wire" plugs in the last 20 odd years.
About a week before installing them I was watching some hot rod tv show where they were testing OEM vs, Iridium spark plugs in a performance engine with various lab test equipment. The results showed not only a 4 horsepower gain (in a 350hp engine though), but also a very slight (.07%) increase in fuel economy. They then showed the difference in spark the two plugs make...the Iridium plug was much brighter and had a much thicker spark than the OEM plugs.
So they glow brighter and in a 150 hp 4 cyl you'd see a 2 hp gain? This reminds me of teenage boys comparing a certain part of the male anatomy and one crowing because his was 2mm longer. I think I will stick with the $3.00 dealer plugs. Let's see. What do those cost per mile over a 30,000 mile change interval? Good luck getting those Iridium "glow plugs" out after they've been in for 50,000 miles or longer -anti seize or not.
lol...nope, don't have or believe in cyclone thingy's.
The Iridium plugs are designed to last 100,000 miles. And I don't believe I'll have any problems removing them at that point. I've dealt with tough plugs before.
The OEM plugs will work just fine. Indeed the ones I removed were in perfect condition for the time they were in. Like I said twice before, I was a skeptic of plugs touting they could do so much....but I'm not a skeptic anymore, and neither are a growing amount of professional mechanics.
Strange that it would develop an unhappiness months later. Or that one plug would be unhappy and the other not. Sounds more like a faulty wire connection problem to me.
Did you check your gas mileage at all, or notice any other improvements?
Well I must be a traditionalist. I have 153M on my 98 (auto) 4x4. I got
150M on my original oxy sensors (only changed them because they were old!) and CV boots. Have always used Toy oil filters, plugs and that pink coolant. Getting 20mpg even though the gov says it's a clunker. Plan on keeping it another 12 years. The original seat fabric is starting to wear a little thin; other than that it looks like new. Oh yeah; no body rust either. Of course our 7" of annual precip (all rain) helps too.
The claim is a increase of four horsepower, not two.
The claim is so full of shit I can hardly know where to begin. There are no tests that I'm aware of that show Iridium spark plugs provide greater horsepower for any gasoline-powered engine that exceeds dynamometer error margins. The error bars widen as RPM increases and/or torque decreases, and every Iridium spark plug test so far published falls well within those error bars.
Testing done at 6,000 RPM for 800 foot pounds and 500 foot pounds (a common test for horsepower) give a margin of error greater than
7 horsepower (roughly 7.22hp). The claim above is for an engine rated at 350 horsepower, which means one will see test results from 343 to 357 horsepower for that engine: a difference of 4 horsepower is what one expects with no change to the engine at all.
None of the tests publish were double-blind: the people testing the Iridium spark plugs knew which test runs had the OEM spark plugs and which test runs had the Iridium spark plugs--- that renders the tests invalid. Only a series of doube-blind tests, where the people testing the spark plugs have no idea which set they are testing, are valid---- and a series of 4 or 6 double- blind tests would be required before any confidence at all in the results may be applied.
Sellers and promoters of Iridium spark plugs do not dare publish the results of properly controlled double-blind tests.
As for the people who claim they can "feel the difference" with Iridium spark plugs in their cars..... well, they're just stupid.
Definitely not a wire or connection problem - and I've been a licenced mechanic since 1971 - wrenching since I was 15 in 1968. The misfire was getting progressively worse. When I first noticed it, there were not even any "incipient" codes registered on the ECU. When I decided to really dig into it was after it misfired regularly enough to actually set the code and turn on the CEL. The misfire only occured under 1500 RMP and basically under 1200 - at or just off idle in gear only. If I reset the ECU and drove down the highway there was no misfire detected - so I doubt there was MUCH effect on mileage. Spark plugs can be strange - years ago in the days of leaded high sulphur fuel we had lots of trouble with plugs "glazing" - a light yellow-green glaze would build up oin the insulator cone that was a semi-conductor and under certain conditions would short out. The coating was Lead Sulphide - otherwise known as Galena
I suspect there was something similar going on with these plugs, although there is no lead in Canadian motor fuel any more. Sulphur levels are getting much lower now too - but PERHAPS I may have put some aged 2 stroke fuel into the tank in low quantities that was mixed from 100LL AvGAs. It would have only been a couple of liters at most of 50:1 in 50 liters of unleaded regular so I doubt that was the mechanism involved - and the insulators looked PERFECTLY clean.
At any rate, one plug either shorted or would not fire when reverse polarized.
Actually, to be totally frank, just because the OEM uses a particular part does not NECESSARILY mean it is the best. There is a price/advantage ratio that works best for manufacturing. There ARE parts out there that are better, at least in some ways, than the OEM parts, for certain applications. They generally cost more than the OEM spec part, or would require payment of licencing fees in order to implement.
HOWEVER - Generally speeking, the OEM spec part is the best bet for general use. When I'm working on a Ford I'll generally use Motorcraft plugs. On a Toyota NipponDenso or NGK (both OEM options) and on a GM, AC Delco.
Whatever the factory supplies - that way the customer can't come back on you if your "flavour of the day" has a problem.
On my own vehicles I sometimes (heck, over the years OFTEN) try different combinations - particularly when other specs have been modified. My '63 Valiant 170 (206RWHP) would chew up and spit out Champion rn14y plugs in 200 miles. The coldest Champion I could buy (n6?) lasted about 500 - so I put in the Nippondenso W24EP plugs. The coldest NipponDensos Toyota used back in the '70s. Those plugs would go 6 -10 thousand miles in the Valiant with no problems at all. The engine routinely saw 6000 to 6500 RPM (and over 120 MPH)
Put them in a stock 170 slant six and they'd be fouled up in no time flat. In town, trying to idle sedately in traffic, they loaded up even on the warmed over engine. So even on that engine, for city driving they were not ideal - but the car spent more time on the highway, or locked in low gear around town
- and I spent less time and money changing plugs.
I ALMOST broke down and installed capacittive discharge ignition so I could install marine surface gap "stones" - no heat range - stone cold.
If the iridiums do the job for you, excellent. They ARE a better plug than a standard or copper core Champion. A fine wire electrode plug will fire more consistently with lower voltage than a standard thick-electrode plug. They are more foul resistant too - we used paladium fine-wires in 2 stroke engines back in the sixties because they would start consistently in the cold (snowmobiles) even with the oil fouling issues 16:1 pre-mix brought to the table.
They are still used in 2 stroke ultralight aircraft engines, particularly when the engine is installed inverted (plug down) because they will still fire when oil soaked.
And no, they were not GENERALLY standard OEM equipment in either application. But they worked. Well enough to make what I remember was their EIGHTEEN DOLLAR price tag in 1969 (compared to something like a buck and a quarter for the stock plug, and seventy five cents for a champion automotive plug) worth while.
Yes exactly. Sometimes OEM is perfectly adequate, and sometimes you want something better.
I also changed tires on my Toyota because I thought they were cheap junk for my application.
I also lifted my Toyota because I didn't like it's low stance. So naturally some people would say; "if you lift it, it won't handle right". Well it handles just like stock, and along with the tires gives me the extra ground clearance and traction I need for these north east winter snows to go where no 2 wheel truck or car drive could go....to my parking lot!
Absolutely correct. Manufacturers have to watch their bottom line price of what they put in automobiles. So sometimes they put some cheap stuff on them.
Maybe you can explain how it is that when they test Iridium plugs against stock plugs, the tests always show an increase in HP and not a decrease that would obviously manifest itself 50% of the time?
Of course, if it did consistently show decreases, mechanics wouldn't leave them in, nor have any reason to promote them. I don't see mechanics or advertisers promoting vortec cyclones on NASCARs.....because they don't work.
Nothing you wrote can be falted; however, the issue is the claim that the Iridium spark plugs increase horsepower, which they do not: there is no evidence showing such an increase. One of the astonishing things about the automotive after-market parts world is that people will spend a hell of a lot of money for crap that is no better than what the car came with, yet the victims of the fraud will defend the product and defend the crooks to defrauded them because they have an emotional as well as financial investment in the product or service.
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