I am thinking of switching to Denso Iridium plugs
Are there any issues I should be concerned with

If you don't know EXACTLY how to gap them properly, you could unknowingly crack the center electrode and have it get blown through the engine in use.....which would be bad juju :huh: :eek:

I dont plan to change the gap
I plan to use the stock part

Is there still a problem

A: On what car?
B: Don't waste your money.

I have a 1995 Legacy and a 1997 Impreza both 2.2 L

Can you specifically clarify what you mean by dont waste your money
Is there no improvement in anything at all ?

thanks

If you read the Spark Plug FAQ that is stickied on this forum, you might find some additional help.

Based on my research, there is no concrete proof that any spark plug manufacturer or spark plug type is "better" than another. By better, I mean more power. There are longevity differences between spark plug types, but otherwise, that is the main concern.

If memory serves, there are/can be some issues with iridium plugs, but they are generally associated with high HP vehilcles when tuning them to the edge.

Personally, I would recommend a copper plug for people who don't mind changing plugs every year, or platnum plugs for people seeking longevity. Iridium is fine, however I don't feel the increased cost justifies their useage over the cheaper alternatives.

You'll not notice an advantage in the iridiums. Get some NGK V-Powers, copper. Turbos take the platinum.

Originally posted by orndog
You'll not notice an advantage in the iridiums. Get some NGK V-Powers, copper. Turbos take the platinum.

Misinformation.

The iridium plugs are a long life plug. They may well last 100k miles in a properly running and tuned engine.
Platnium are of the same nature....long life, but maybe not 100k miles.
Copper plugs are a shorter life plug, that may provide some enhanced performance over the others at the cost of service life which may be as little as 5-6k miles in very severe service....or 20-30k miles under(more) normal usage.

New sparkplugs should ALWAYS be checked for proper gap prior to installation even if supposedly 'pre-gapped'.
That could be a VERY expensive lesson to learn...

How was that misinformation? I stand by what I said, he won't notice a benefit of buying iridium plugs. As for coppers lasting 5 to 6k miles, in a car running that crappy, I gurantee plats wouldn't last much longer.
Plats in a block for 100k miles tend to have a problem with seizing in there, running the risk of screwing up your threads. Also, spark plugs are a great thermometer of engine performance. Taking them out often is a good way to guage the running condition of your motor.
Coppers run better than plats in our NA motor as well.

The statement...:

Originally posted by orndog
You'll not notice an advantage in the iridiums. Get some NGK V-Powers, copper. Turbos take the platinum.

....is incorrect.

The 'advantage' of iridium(or platnium) plugs is long service life. That is a distinct advantage over copper.

Copper plugs can be used in any engine, and should be used exclusivly for some applications such as nitrous oxide injected engines.

Platnium plugs are not just for turbo applications.


SOOOOoooo....your statement(s) is(are) false and misleading, and thus misinformation.

How about the Silverstone spark plugs ?

I didn't say all plats were for all turbos. I meant that for the Impreza, plats are recommended for the turbos, while coppers are for the NAs (iirc). Personally, my old Legacy ran a little "funny" on the plats, though I admit I haven't tried them in my new OBS - and don't plan to.
Service life
Copper plugs - 20k miles.
Plat plugs - 100k miles
Iridium plugs - 200k miles
Advantages of iridium - longer life than platinum, less resistance than platinum. I, and others, say don't leave a plug in there that long anyway. Also, we're talking resistance difference in the thousandths of ohms. Even if that was enough to make a difference, you could get better resistance results by changing wires - or just use the copper alloy plugs. Yes, iridiums are better, there, I said it. But enough better to justify the price? Not to me, but if they are to you, use them.

Nology - silverstone offers this stuff, any of it works ?

1. Nology Hotwires
2. Beru plugs
3. Wire Separators
4. PowerCore Ignition Amp
5. MSD Distributor Cap Adapter and Coil Wire

G.S.: You might want to tell us what model/year car you have, and what effect you are trying to achieve.
For example, you might want to check whether or not your car has a distributor... ;)
In general, those things look like all bling and no bang.

The Harley guys love the Beru plugs....they say they are almost impossible to 'rich' foul out.....and Harleys run more pig rich than Subarus:lol: :huh: :lol:

NGK standard copper go 30,000 miles easy and look very very good in my 2.5L suby. Somebody who get 5-6K has a poor engine.

For $4.99 a pack I use the NGK coppers and go through 2 or 3 sets per season. I just change them out when I'm doing a "maintenance day". They have always looked great when they came out of the car.

On the fiance's STi we have the OEM platinums at 40K and I'll be replacing them soon with with the OEM platinums again. Why mess with a good thing on a street car :)

-Tom

I went to iriduims in my 02 RS because i read that the misfire less than other brands, just something i figured couldnt hurt and changing them isnt all that fun.. No noticed smoothness increase or loss. but 44$ for plugs - theyll stay in a while

The plugs themselves don't misfire, people get less misfires with them because the electrodes last longer/ deteriorate less with time, meaning they keep their gap longer. That's all those fancy metals are for. A plug has to get hot enough to not build up deposits, stay cool enough to not melt or cause predetonation, and resist deterioration to hold their gap.

I just slapped in a set of new BOSCH Platinum +4 plugs (with the 4 prongs) and my car runs great! Feels a tiny bit smoother than the stock NGK's. I also added a set of BOSCH plug wires to replace my old ones (car's at 60K miles now). So far, I've noticed better fuel economy and a slightly smoother engine.

Now, I'm not saying that these are some "miracle" plug, but I guess compared to my old plugs/wires (which I guess were pretty old and run down), my car is just running at 100%, as opposed to 90% on the old plugs.

I have a B4 rsk (2.0lt)in tropical Sri Lanka, I recently put in NGK iridium plugs (4) and the car has a substantial increase in performance..and i also get 1km more per litre!!

NGK standard copper go 30,000 miles easy and look very very good in my 2.5L suby. Somebody who get 5-6K has a poor engine.

:lol: d00d......you are a trip....your lo-po N/A motor can not compare to a proper stage4 motor running 20+psi.....don't try to make any comparisons like that ;)