I am about due to change my spark plugs. So, which do you guys think are better or is it a wash? It is either NGK plats or iridiums.... I need to decide.

 

Spark plugs are all about conducting electricity between a gap to ignite the air/fuel mixture. The better spark you get, the more complete burn you get, and the more power you get out of the fuel you're using. To get a better spark, you need to use a good conductor. Copper is one of the best conductors available for spark plugs, and is dirt cheap, though it has pretty short life span. Nickel and platinum are good conductors but not great conductors, and are used by manufacturers because of their extended life span.

Iridium will last the longest of any spark plug tip material (some are rated up to 100K). Do you really want to wait 100k before changing them again? I don't. Every 30 or 60k works for me.

But...I think the spark plug that was designed for the system by the engineers who designed the system is always the best choice for that particular system. Go for platinums.

 

The original plugs are platinum, which is good for 60k. If you don't want to spend $10 each on the OE NGK's, you can use Denso Double Platinum with confidence. The Denso Platinum TT Twin Tip is also supposed to be good.

Normally I recommend iridium for transverse V6 engines, but that isn't necessary for the 4th gen because the rear spark plugs are easy due to the cutouts in the intake manifold (which means you don't have to remove it). However, there is certainly nothing wrong with using iridium. I'm using Denso Iridium Long Life part number 3395. Denso also makes an iridium TT which should work well (and is OE on some new cars now).

OTOH, the 5th gen doesn't have such a cutout, so you have to remove the intake to access the rear plugs, so in that case you want iridium so you don't have to go back there again for 100k.

 

I'm assuming the same is true for anyone running an 00VI intake?

 

I really like the ngk v grove copper ... my car runs smooth and starts on a dime ... these engines are design around the ngk plugs...your choice

 

NGK LASER IRIDIUM IFR5E11 7994 is the best overall spark plugb that NGK has to offer and it lasts 100,000 miles. This spark plug also comes stock in new nissan vq v6 engines. I have this spark plug in my 97 maxima and it runs much better and smoother than ngk double platinum. You really cant tell that much of a difference between the two but its noticeable. Just get these and forget the worry of changing your plug again till another 100,000.

 

I am approaching 45K on the NGK plats I have now. My inspection is next summer and by then I will have about 60K on them. I would rather do the preventative maintenance now instead of later. The car is running flawlessly, so I hate to mess with it, but they will be due for a change by then. I hate leaving plugs in too many years, even though I put anti seize on them when I installed them..

 

correct

 

x10e^10

Given the fact that yo do not need to remove the IM to get to them and it also gives you a good look at the plugs every 30-60k, I always go with Cu for my 4th gen. And they're like 2-3$ per.

 

BTW, I haven't changed my plugs in about 4 years. Off hand does anyone know the torque spec for our spark plugs?

 

IIRC they're 20ft/lb for my 1998.

Under the Wiz's signature in Post #2 find the FSM link. Click on the year of your maxima then download all the FSMs. The MA.pdf manual will give you the torque specs for the pulgs. Note that you'll find every torque spec for your maxima in these manuals.

I used to install the platinum but with the high mileage on my maxima I switched to copper last fall. I did so because I like to inspect the aging coilpacks more often during the spark plug install. I've already replaced their rubber boots as they got torn away over the years. On one OEM coilpack the plastic nipple were the rubber boot snaps onto broke off last year.

 

I will be going with the platinums since I want to keep an eye on the plugs every 3-4 years. If it was a newer car, I wouldn't be so concerned.

 

I like to use ngk coppers becuase they're cheap and effective. I also like to clean out my air intake/egr system at 30,000 mi or less, so I prefer to change out my plugs for a full tune up.

 

I use platinum, and can also understand the reasons for using iridium.

Everyone has an opinion. Mine is that I like to mess with an aluminum head as little as possible. So if the plugs are not replaced as often, the threads will last longer.

I do not particularly enjoy replacing spark plugs. I like not having to replace the plugs for 60 to 100 k miles.

Most of us will not drive our cars that far before they are sold or scrapped.