Iridium Plugs and Gas Mileage

Marketing, but I guess it is all hype. There are also Ruthenium plugs.
i bought the ruthenium plugs because they were cheaper than the double iridiums. if the spark plug conducts electricity and has the proper gap then it'll work perfectly, until it wears down an the gap is too big.
 
I wouldn’t trade the MPG for cam phasers or AFM.
The phasors on the Ford 6.2L are a different design. They do not operate on oil pressure. The operate using the tension of the valve springs pushing the cam forward or backwards. The solenoid opens just to fill the void split with oil, and the cam is rephased. There is no AFM either. It replaces EGR, which could have issues too.
Very rare to find one that failed.
 
pointy plugs run better, it may require less fuel.
but pointy plugs would wear quickly, therefore special metals.
with new engines already have pointy ir plugs, you cant buy fat plugs for new car.

in old car i tried https://www.brisk.eu/catalogues/spark-plugs/premium-zc-zs
swieca-zaplonowa-brisk-premium-dr15zc-tuning_21621.webp

but this ran better
A9340190-3.jpg
 
If this continues - tiny SawsAll‘s will be developed and they will cut the tops off at motels …
 
I think the O.P. is simply going to have to try the Iridium plugs and see what happens. 16 plugs is an expensive experiment. The hope is to not get poorer MPG.

Some modern Ford engines are very sensitive to the exact spark plug, others not. Specifically EcoBoost. So perhaps that is what taught the O.P.'s Ford dealer to fear anything not Motorcraft?
 
The phasors on the Ford 6.2L are a different design. They do not operate on oil pressure. The operate using the tension of the valve springs pushing the cam forward or backwards. The solenoid opens just to fill the void split with oil, and the cam is rephased. There is no AFM either. It replaces EGR, which could have issues too.
Very rare to find one that failed.
Correct. The only way to get better mileage is go to a design that has issues compared to what is essentially the best truck engine Ford came up with in decades is to go with the Ecos or GM/Ram and those issues are well documented . Spark plugs won’t gain much unless they’re worn down to nubs like my 6.0 Yukon was. Even then it was nothing miraculous. I’ve been down this rabbit hole before just for fun even though I knew what the outcome would be. I wish my GM 6.0s got better mileage but 15mpg at 75mph is pretty good for a 5500# vehicle.
 
I have a 6.2L F150. The gas mileage is 15-16ish mixed driving (short trips less). Last Tuneup was about 80K miles ago. Motorcraft specifies a double platinum. Thinking of going with an NGK or Denso Iridium. The Ford Place here advised not to, they said the Motorcraft is application specific for that motor (it has 2 plugs per cyl). They only install M/C plugs or not do the work. I am looking to increase gas mileage. M/C plugs for that motor are also priced almost at the bottom on R/A.

The coils also have an additional inline fuse resistor, maybe that won't work with other plugs?
Put new Iridiums in my truck and, no gas mileage increase at all.
Was hoping but, didn't happen.
 
I think the O.P. is simply going to have to try the Iridium plugs and see what happens. 16 plugs is an expensive experiment. The hope is to not get poorer MPG.

Some modern Ford engines are very sensitive to the exact spark plug, others not. Specifically EcoBoost. So perhaps that is what taught the O.P.'s Ford dealer to fear anything not Motorcraft?
The Ford place said they had a comeback once with different plugs, and possibly thousands of no issue for the fleet 6.2L with a 100K spark plug interval (the required plug). According to them some of those trucks see 500K.
According to them the size will interchange but SP526 is made special for that truck. Likely will use that, the price is right too. Denso 4719 actually interchanges with all F150 engines made in 11. (incl the Eco).
 
My ford takes platinum from the factory. I switched to irridium plugs from almost new oem and saw +10% mpg and performance. I also have high voltage coils and ecu tuner which may have helped.
 
Computer controlled, injected engines and modern head designs don't have a problem igniting the mixture, pretty much any spark will do the trick.
You could probably make a spark plug out of a coat hanger, a cork and some aluminum foil and it would work.

So no plug will make a difference in mpg, since there is no leverage anymore at that point.

With a vintage motor, head/intake design, carb, traditional ignition etc. - yes, fiddling with plugs could make some difference, but not in a modern car.
 
Is it possible they are claiming the better mileage as the result of the electrodes being more wear resistant, thus keeping the plugs from misfiring longer than a 'standard' plug ?
 
You’ll never see a difference in fuel usage unless the plugs you’re using are truly crummy plugs. The different plug designs and materials are primarily for longevity. Use the plugs that the manufacturer specifies for the engine.
This, all day long. The auto manufacturers are struggling to get even 1/100 MPG better mileage. If other brand plugs got better MPG don't you think that they would be using them?

Years ago when I had a lot of excess time on my hands, I bought a set of every brand plug that I could get and a tried them all in a couple of cars that I owned at the time. (Yes, I'm a discliple of Smokey Yunick.) The Autolite plugs were consistantly the best even though the manufacturer usually called for Champion plugs. I tried all of Platium and other gimmick spark plugs such as the ones that had two grounding electrodes but in an engine in good condition none of them gave any improvement over the Autolite plugs. Motorcaft and Autolite make excellant products IMO. If that's what you're vehicle calls for then IMO you should stick with them. OTH, you're free to experiment and then report your results back here.
 
This, all day long. The auto manufacturers are struggling to get even 1/100 MPG better mileage. If other brand plugs got better MPG don't you think that they would be using them?

Years ago when I had a lot of excess time on my hands, I bought a set of every brand plug that I could get and a tried them all in a couple of cars that I owned at the time. (Yes, I'm a discliple of Smokey Yunick.) The Autolite plugs were consistantly the best even though the manufacturer usually called for Champion plugs. I tried all of Platium and other gimmick spark plugs such as the ones that had two grounding electrodes but in an engine in good condition none of them gave any improvement over the Autolite plugs. Motorcaft and Autolite make excellant products IMO. If that's what you're vehicle calls for then IMO you should stick with them. OTH, you're free to experiment and then report your results back here.
How dare you actually experiment and bring facts and experience to the internet!
 
I have a 6.2L F150. The gas mileage is 15-16ish mixed driving (short trips less). Last Tuneup was about 80K miles ago. Motorcraft specifies a double platinum. Thinking of going with an NGK or Denso Iridium. The Ford Place here advised not to, they said the Motorcraft is application specific for that motor (it has 2 plugs per cyl). They only install M/C plugs or not do the work. I am looking to increase gas mileage. M/C plugs for that motor are also priced almost at the bottom on R/A.

The coils also have an additional inline fuse resistor, maybe that won't work with other plugs?

Of course they advised not to, they can't make the extra money on the 200% markup for non Motorcraft parts.
I've been putting Ruthenium plugs in my fleet of Fords, same price as Iridium with better longevity.
 
Of course they advised not to, they can't make the extra money on the 200% markup for non Motorcraft parts.
I've been putting Ruthenium plugs in my fleet of Fords, same price as Iridium with better longevity.
NGK 90495 (Ruthenium, Fits pretty much every Ford) at Rockauto is $8.70. IR's are $4-$6. The Double Platinum OEM is $3.98.
 
The theory is the plug will fire hotter with a more concentrated spark and hence burn the mix better. Both are technically not lying but still wrong.

An iridium plug won't do much extra unless you upgrade your ignition system - primarily the coils, to take advantage of that plug.

Even if you do, on a closed loop control system its going to be held to 14.7:1 stoycheometric ratio by the control system. So a better plug isn't going to burn more efficiently, because the control system already controls the mix - unless as mentioned there was an issue before. If the current plug isn't burning the mix properly you should see that on your long term fuel trims - which might be worth looking at before you do your plug swap - just to have a benchmark.

You can try them, and I am sure you can find an iridium that will work fine - but you likely won't see an increase in mileage any better than new OEM plugs would provide - if either provide any bump at all.
And upgrading an ignition system to one with more power to the sparkplug results in more load on the alternator and that puts more load on the engine which could result in less MPG's.

If the existing ignition system is burning all the fuel properly then adding load to the engine would reduce MPG's.
 
And upgrading an ignition system to one with more power to the sparkplug results in more load on the alternator and that puts more load on the engine which could result in less MPG's.

If the existing ignition system is burning all the fuel properly then adding load to the engine would reduce MPG's.

Not true. The vehicle runs off of the battery not the alternator. The alternator just keeps the battery full.
 
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