NGK iridium vs platinum

04Crimson-GT said:

Although the engine is firing and running well, I know that, at 65,XXX miles, I am being robbed of mpg as well as power.

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Actually, that's probably not true. If the engine is running fine, the fire is being lit and the plugs are doing their job. You'd be better off to ensure the front O2 sensors are "fresh" rather than the plugs and even then, if the PCM isn't setting a code (MIL on) it's not unhappy with how they're performing.

I have looked around and came across the NGK iridium plugs and the platinum plugs. The only engine mod I have done is a JLT ram air intake (if you really consider this a mod), but am definitely planning on doing much more. The platinum plugs cost about $30 whereas the iridium plugs cost $70 so my question to you guys is, is it worth the extra money to go iridium or should I just save my money and go platinum? I know the difference between the two, but would like some input on which direction to go.

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I wouldn't use either. Not worth it IMHO. Platinum tipped plugs are good for OE installation where the factory has to ensure they last the life of the emissions warranty or 100,000 miles. I'd personally never wait that long to replace any plug and so spending money on one designed to last that long is pointless.

I'd stick with Motorcraft (Ford) replacements for stock. With my blower I've gone a step cooler to help stave off preignition concerns and went NGK but I'd otherwise just make a trip to the Ford parts counter for OE plug replacements. You will not notice any difference in power or efficiency with fancy-schmancy platinum or iridium plugs.

You will probably be surprised at how good the plugs you're about to remove look when you get them out. By the way, when replacing the plugs, it's imperative that you (a) use a torque wrench and tighten the plugs to the proper, rated torque and (b) that you go back after a few hundred miles and re-check the torque to make sure none are backing out.

Excellent post by Trinity GT . While a copper plug won't last as long as the platinum or iridium tipped plugs, by going with the cheaper 12 month plugs, you'll get the 'opportunity' to check your plugs more often. The plugs condition can tell alot about what's going on inside your engine. And copper is a better conductor anyway.
If you were to add a power adder (supercharger, turbocharger, nitrous), you might benefit from the iridium plugs, but, especially WITH the power adder, I'd want to check my plugs even more often...every 3-6 months. Motorcraft plugs are good, but your more likely to find NGK plugs at your local Auto Parts store. And NGKs are good as well.
I've never replaced my O2 sensors and unless they are throwing a code, I wouldn't replace em. But if necessary, I'd go with name brand, such as Bosch. They are sold at Advanced Auto Parts - they should be under $50 each.
Be sure to change your oil on a regular basis, use good oil (be it conventional or synthetic) and a good filter (avoid FRAM). A good preventative maintenance job is to replace the fuel filter. It's absolutely AMAZING how restrictive they can get even after just 1 year. I replace mine every year. You should try blowing thru the old one, then blow thru the new one and you'll see what I mean - very restrictive. Fuel filters are cheap and the job of replacing it is really pretty simple. Of course the first time you do it, you're likely to fight with it a little bit, but then you'll find out how easy it really is once you have done it. Here's a link to an excellent write up on how to change it. You will need a specialty tool - a fuel line tool (A 5/16th inch spring lock release tool ). See this link for great pics and descriptions of the steps involved (note the site is for Bullitt Mustangs, but nearly everything is the same as the GT Mustang)... BULLITT Fuel Filter Change

I would not use Fram oil filters. I have heard bad things about their by-pass plug. I would use K&N or wix filters. As far as regularity in changing fuel filters it is what everyone considers regular maintenance. I change mine every year just because I can afford to do the easy replacements. Then again there are people who have gone 3, 4, 5 years before changing a fuel filter, ( but I wouldn't).

Ha. It's funny we're talking about fuel filters. I just changed mine last night. First time in the 3 1/2 years I've had my car (only about 15000 miles though...). And yup, it took me a while to do it (about an hour or so), but if I did it again I could probably do it in 10 minutes flat. One big piece of advice: relieve the fuel pressure from the system before taking it off...

-Will

04Crimson-GT said:

So even if I added some more bolt-ons in the future, would I still not benefit from either plugs? I am definitely going to add more to the engine in the future and just want to make sure that I get the most out of each mod.

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If you bolt on a power-adder (supercharger, turbo or nitrous) you would want to go a range cooler on the plugs and narrow the gap from 0.054" down to ~0.035" (upgrading the COPs (coils) may allow you to run a higher gap) but other than that, no, you won't see any performance increase if the fire is being lit by the current plugs and your PCM will let you know that's happening by flashing the MIL and/or when a P030x code gets set.

I know that many people may overlook some small things like the spark plugs when trying to produce more power. I don't want to overlook any of this, but if I will see or feel no benefit from either plugs then it obviously doesn't make sense to spend more than necessary.

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In simplest terms, the spark plug is there to provide a place for the spark that initiates combustion. Once combustion has started, the spark plugs job is done until the next cycle. High compression pressures (especially those associated with forced induction) can increase the voltage required to jump the gap; if the COPs are not up to the task, you may get misfires. Compensating for the increase pressure with a reduction in gap (see above) can mitigate this but of course at the same time you want to maximize the gap to maximize the amount of mixture exposed to the spark and thus the chances of a good, sustainable kernal being lit. Another way to reduce the voltage requirement is to provide sharp edges on the electrodes: in HV electronics, sharp edges mean high field values and a better chance of ionization.

Some fancy plugs (e.g. "V-power" types) attempt to provide these added, sharp edges with varying degrees of success. However, simply installing a fresh set of "conventional" plugs gives you all the nice, crisp sharp edges needed. Over time, normal combustion erosion will round the edges of the electrodes which will lead to higher and higher firing voltages. This is where the benefit of replacing plugs really comes in.

Years and years ago we used to remove plugs, file the electrodes to restore the edges and re-gap them. We even used small, dedicated media blasters that would blast the plugs to remove built-up carbon and deposits from the electrodes and insulator, ensuring no "short circuit", low-voltage path existed to cause the juice to find an alternate route to ground. Of course, nowadays it's cheaper and easier to simply replace with new.

Say my front 02 sensor needs replacing, what recommendations do you have in terms of brand and/or place or site to get it at? Again, forgive me for being new at this.

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I don't think you can go wrong with Bosch, NGK or OE for oxygen sensors. But as has been said, wait until the PCM tells you a sensor has gone bad.

Dustys'99 said:

I would not use Fram oil filters. I have heard bad things about their by-pass plug. I would use K&N or wix filters.

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I've only had good experiences with the OE Ford part. It seems to have a superior anti-drainback valve to other filters and helps keep the engine from sounding like a Powerstroke diesel after cold starts.

Best thing I can say in this thread, being a ford mechanic is MOTORCRAFT, MOTORCRAFT AND MORE MOTORCRAFT. Unless your using a blower, get motorcraft plugs, absolutly nothing wrong with them; and as stated before, make sure you torque them to spec otherwise you'll find yourself at the dealership either having you head heli-coiled or being handed an estimate for cyl head replacement.
As far as fuel filters go, they should be changed every 30k miles or so, depending on your driving. If you do less than 10k miles a year, or more stop and go driving i'd change it more often.
For oil filters, its imperative that you use motorcraft filters. Ford Motor Company has stated more than enough times that you should not use aftermarket filters, otherwise you will get engine noises and in more severe cases, internal engine damage can occur, especially on the 3 valve engines.

I have NGK iridium plugs in both my Cobra & GT, use STP oil filters & synthetic oil (usually Royal Purple 10w30, else STP full synthetic). No problems with any of the above for 80k miles in the GT, and 25k miles in the Cobra.

I have used Mobil One Oil Filters on every car for the last 20 years with synthetic and except for my mustang, change oil at 8K-12K miles or more. Haven't had a single issue and never had an engine issue at up to 250K miles. Those cars either got wrecked or stolen. I was hoping my Windstar did that but some butthead wrecked that at 180K miles and my current Windstar has the tranny not staying in overdrive after it warms up so I may never get to find out if the engine makes it.

I tried the NGK TR-55 iridiums and really liked them. I thought I could feel a difference... but... they are expensive. Because I'm blown now, I use NGK T-6s, for some reason a lot less expensive.

One thing about oil and oil filters. Doesn't matter how good your oil is unless you have a good filter.

Fram =

I use only K&N for their quality and the easy built in 1" nut on the filter for removal/installation.

Fuel filters are cheap and should be replaced yearly around the same time just to be sure. Lot's of different blends of gas over the seasonal year and lot of garbage in gas depending where you are getting it from.

Don't buy O2 sensors till you need to and then buy them in pairs (right/left) and don't go cheap.

PCV isn't expensive to replace so go for it.

Welcome to the club! :SNSign:

For my blown Mustang, I use Autolite 764's gapped at .035. Cheap copper tops that cost 18 bucks for 8, and change them out every 6000-8000 miles. These are what Paxton recommends.

I've had great luck with the NGK Iridium plugs. I found they smoothed out the car - especially at idle. A lot of the Cobra guys have the same experience.

When I was N/A I ran the TR55IX and now that I'm blown I run TR7IX. I tried the BR7EFS and my car didn't like them at all. It ran rough and stumbled off-idle quite a bit.

Riley

This is the plug I took out after about 1500 or so miles. Do they look OK?
I have a S/C so I replaced them with one range colder plugs over this stock one.