spark plugs

[Nedflog]

'97 Max with 102,000 miles and the original spark plugs. Anyone have a good suggestion on replacement brand and type?

[240TweakerNewbee]

If you don't like changing them too often, as its obvious you don't; I would go with Denso iridiums or NGK iridiums. But even those arn't good for much over 50k miles. Are factory plugs copper? If so, that is amazing that you got them to last that long. After 102k miles You should think about changing out the rest of your igntion system too; Wires, rotor...etc.

[MinisterofDOOM]

Welcome!

No denso. NGK only. NGK Platinum or Double Platinum are the best option.

[maxhopper]

OEM replacement is NGK part # PFR5G-11. You can order them from http://www.sparkplugs.com for a good price.

[Nedflog]

Do you think OEM is the way to go or is there something better; perhaps something that has been developed in the past 10 years that gives a more efficient spark/better mpg?

[maxhopper]

Nope, stick with the OEM NGK. Your engine will thank you.

[jmaxima]

The Denso will work fine, but isn't authorized by Nissan. The NGK platinums provide exactly as much performance as the car needs and last twice as long as the Iridium, 60k versus 30k miles. Early '97 and earlier 4t gens had a different ignition than latter 4th gen Max's. So check for your specific car / VIN to get the right plugs. I think the plug that is noted above is for the later 4th gens - looks like a familiar model number to me anyway.

- James

[Chris92SE]

Maximas (except for the VG30E cars) have coil on plug, which tends to be kind of picky. I would stick with NGK. I have had a Nissan Tech tell me that some other brands (bosch he specifically stated) can cause problems with the coil packs.

If you do maintenance yourself, there is nothing wrong with using copper. The cars come from the factory with platinums, but that is for durability and so they can advertise longer periods between "tune ups."

I use coppers and I just change them more frequently. At about $15 a set for coppers or $75 for a set of platinums, it's easier for me to shell out $15 every year or so, instead of that big hit. I never really worry about them getting weak or having problems, since they get replaced before they wear out at all.

Also, Platinum is not recommended for use with nitrous, in case any of you are thinking of spraying.

[C-Kwik]

The Denso will work fine, but isn't authorized by Nissan. The NGK platinums provide exactly as much performance as the car needs and last twice as long as the Iridium, 60k versus 30k miles. Early '97 and earlier 4t gens had a different ignition than latter 4th gen Max's. So check for your specific car / VIN to get the right plugs. I think the plug that is noted above is for the later 4th gens - looks like a familiar model number to me anyway.

- James

I recommend reading the following link and the iridium technical pdf and the the pdf of the mustangs and fast fords article at the bottom.

http://www.sparkplugs.com/spar...fid=0

To sum up though, iridium is harder than platinum. The problem with iridium lies in it's oxidation properties. The technical pdf will explain this in great detail. But denso uses iridium with a 10% platinum content to virtually eliminate the problems with oxidation. As a result wear is reduced. The iridium plugs do use a thinner center electrode though than platinum plugs. The advantage of a thinner electrode is that less voltage is needed to allow the spark to occur. With the harder, more wear resistant metals used, the plug will be able to last as long or longer.

There are exceptions however. Cars with coil packs spark once from the center to ground electrodes and then once from the ground to center electrode. For this reason, double platinum electrodes are used by OEM's that require platinum plugs. These will likely outlast most iridium plugs. Though NGK is starting to make double iridium for the OE applications that are starting to arise. I'm not sure if they are going to try and increase life further over Pltinum or simply increase performance by decreasing the voltage needed and/or widening the plug gap exposing more the the spark to the mixture.

Another exception may be the denso plugs. They use a smaller center electrode than NGK, which results in even better performance. Wear does not appear to be great, but better than a standard copper plug. The reduced wear comes from having less metal on the electrode.

I recently switched to iridiums. Admittedly, I was looking for platinums at the local auto store, but they were sold out. Iridium NGK's were the next best option. After a weekend of driving, I found they are smoother than the platinums I pulled out. The platinums didn't appear to be worn much, if at all. I did my iridium research after I bought them. According to a couple sites I found info at, single platinum plugs can be expected to last about 60,000 miles.

The impression I get is that iridium plugs are currently being produced mostly for a cood balance between performance and wear. Though the denso's may be even more towards performance. you can expect wear to be better than a standard plug.

[NosKid_13]

Go with the NGK plugs there OE and you can find them at Advance Auto Parts or NAPA for about $7. also go to nopi.com they sell NGK plugs.
Modified by NosKid_13 at 8:25 AM 10/3/2006