Spark Plugs

[Onslaught31]

I want to change out the stock plugs for something more efficient and maybe squeeze a little power out of the car. A friend of mine swears by Bosch Platinum +4 plugs, I'm inclined to believe him since he worked as a pit crew leader in nascar for 12 years, but everything I've heard says they suck in performance cars and imports. Many people have referred me to NGK plugs, and I've also looked at Splitfire plugs as well.

Has anyone changed theirs out or know anything about them?

Justin

[Beancooker]

Stick with NGK. Bosch plat4's don't work well in our cars. You'll get the best performance from the NGK's.

[szh]

Nissan and Infiniti engines are notorious for disliking Bosch spark plugs. Please do a search for why you should stick with the OEM brand ... your engine will thank you!

You can get hotter plugs. The Service Manual gives you the two options of NGK plugs that you can use ...

Z

[Gimli G35]

NGK work very well , and OEM are good also lol

everyone i know uses NGK

[szh]

NGK work very well , and OEM are good also lol

Yes, I am pretty sure that the OEM plugs are NGK.

Z

[g35sedanlover]

For the sedan, I am seeing 3 different plugs (all NGK):

Standard type PLFR5A - 11Hot type PLFR4A - 11Cold type PLFR6A - 11

Which should I use? Is their ups and downs to choosing a hotter or colder plug?

[C-Kwik]

The combustion process in a cylinder is highly analyzed by car manufacturers. The Bosch Platinum 4's are very different in layout and may not work well with a more traditional electrode layout.

My own experience on a 240sx with those plugs were quite bad. At idle, I'd feel and hear misfires constantly. Switched back to my worn plugs and it ran much better.

[gwoods]

For the sedan, I am seeing 3 different plugs (all NGK):

Standard type PLFR5A - 11Hot type PLFR4A - 11Cold type PLFR6A - 11

Which should I use? Is their ups and downs to choosing a hotter or colder plug?

Use the standards, the colder range plugs are for nitrous or turbo. Not sure why you would want a hotter range plug?

+1 on the NGK!

Jeff

[g35sedanlover]

The OEM is the "Laser Platinum" but NGK also offers V-power, G-Power and Iridium IX. The G-power also has a platinum tip (like OEM) but seems to be the next step up. Has anyone tried any of these NGK plugs?

[gwoods]

I only have 21k miles so not yet but I'll probably try them when I get closer to 40k.

[infinititech1]

ONLY use ngk

[adren77]

After how many miles should one be changing their spark plugs on a G as part of regular maintenance?

[g35sedanlover]

Manual says after 100,000 miles. My poor G is at 95,000...

Infinititech1:I plan on using NGK but they offer different series of plugs. There are two platinum plugs, the Laser-Platinum (OEM) and the G-Power. The G-power seems to be a little better plug, is it better for the G? It seems to have a similar design as far as shape.

[infinititech1]

honestly ive heard factory plugs are the best way to go cause that is what the car is meant to run on....

[gwoods]

Platinum tipped plugs CAN last up to 100,000 miles I change mine at every 40,000, do transmission service every 20,000.

Jeff

[precision93]

Check the FAQs on the NGK website. Changing heat ranges will only benefit if you have extensive modifications.V and G power are conventional plugs ($2 each) compared to the platinum (@ $20 each), thus not as good.

Spending @ $120 for different plugs (platinum) will be much better spent on a different mod. NGK website also says not to expect much of any gain by changing plugs.

[g35sedanlover]

So your are saying I shouldn't replace the plugs, even though I am at 95,000?


Modified by g35sedanlover at 3:05 PM 12/5/2007

[joshcloud9]

If you look at this page on NGK's site it looks like this plug is exclusivly designed for Nissan!

http://www.ngk.com/results_fit...%2D11

[Road Ruler]

I see Canadian tire here in Ontario has the NGK Iridium IX Spark Plug listed.

NGK claims they are the most technologically advanced high performance plugs available. Looks like price is $12.00 a pair.

They seem to be a step up from the OEM NGK platinum plug.

http://www.ngksparkplugs.com/a...24496

[gwoods]

So your are saying I shouldn't replace the plugs, even though I am at 95,000?

Modified by g35sedanlover at 3:05 PM 12/5/2007

I'd replace plugs every 40,000 miles it can not hurt. Heres a couple tips.

Make sure the engine is cold!

Use some penatrating oil like "nuts off" or "liquid wrench" soak the plug wait a couple min then try to remove them.

Use hand tools and take your time to make sure you are not at an angle. I'd start out trying to get the old plugs out with 1/4" drive socket set first cause the last thing you want to do is break a spark plug off in the head. Its hard to build a lot of torque or leverage with 1/4" drive tools.

Put a dab of anti seize on the threads of the new plugs. Put die-electricgrease on the coil/boot end of the new plugs. Make sure you get the boot/coil fully seated onto the end of the plugs.

Jeff

[gwoods]

Get the factory torque rating and make sure you do not over tighten the new spark plugs. Use a torque wrench your probably going to need one that is inch pounds of torque instead of foot pounds.

Even though the new plugs come gapped, check the gap. If the box was dropped once before you bought it there is a small chance the gap is changed. You may loose performance with the spark plug change if even one plug is gapped wrong.

When you install the new plugs start them with your fingers and work them back and forth a couple times before using tools. If the plug stops turning easily at any point STOP. The head is aluminum and the spark plug can strip the threads very quickly.

Oh and TAKE YOUR TIME doing this job. You can really F up the cylinder head changing spark plugs and your not going to have a lot of room to work on #5 and #6. There is no shame in letting the dealership or a shop do this job for you.

Use the OEM plug, you will not gain performance by changing spark plugs, you may recover some lost performance by replacing the OEM plugs if they are worn. Using a non OEM plug could loose some performance. The only way to make more power is to increase the engines ability to efficently burn fuel. There is no such thing as a high performance spark plug.

Jeff

[g35sedanlover]

I just ordered new stock plugs. Has any one replaced them and noticed a change? (getting back lost power, cleaner idle...)

[tollboothwilley]

The OEM is the "Laser Platinum" but NGK also offers V-power, G-Power and Iridium IX. The G-power also has a platinum tip (like OEM) but seems to be the next step up. Has anyone tried any of these NGK plugs?

Currently running the NGK Iridium IX

nice and smooth

I'd recommend 40-50K mile changes. For the cost of the plugs, why would you ever risk the lack of performance?

[g35sedanlover]

Off the topic, Have you ever ran your car at a track? We have similar mods...

[Jacko3]

ONSLAUGHT31:

My mechanic has specifically told me not to use anything else but OEM NGK plugs. He has detailed tons of cars that come into the shop with a different type of spark plug, with problems. When they change the spark plugs to OEM NGKs, the car suddenly runs better. So, use OEM plugs. They are good. Also, I agree that 40,000 miles is about right for a spark plug change. The 100,000 mile spark plug replacement in the manual, seems spurious, especially if you drive your car very hard. Also, my mechnic tells me to do my differential oil between 20,000 and 30,000 miles.

[BrandAidDesignG35]

Holy crap guys... I was used to changing plugs in 10 - 30 mins...

I saw a 30 min accelerated video on youtube with detailed instructions, I know I say I always like to do the work myself, but the time involved is crazy, I think I'll take mine in to the dealer... lol

Jacko - how hard is it to change the diff fluid? time wise, I'm just thinking while I'm in I'll kill two birds with 1 stone.

Grant

[C-Kwik]

Currently running the NGK Iridium IX

Bear in mind that the NGK Iridium IX plugs use only an iridium center electrode and a standard ground. The OE plug uses a platinum center and ground electrode to extend life as engines with coil packs (such as the G35) spark in both directions (center to ground during the combustion stroke and ground to center during the exhaust stroke). While the plug will work, expect that the ground electrode will wear faster than in a double platinum plug.

The only iridium plug available in the states that is going to be long wearing with coil packs are the Denso Iridium SK series plugs. These have an iridium center and a platinum ground electrode. I am actually using these on the Titan and they feel no different than the OE NGK's.

[Jacko3]

Brandaiddesign:

It does not take that long. Your only challenge is finding the right tool to open the drian and filler plugs. Also, don't forget the to use a torque wrench to tighten the drain and filler plugs to correct torque.

[TeflonG35]

Make sure the engine is cold!

I changed the plugs on my old supercharged buick and i dident let the engine cool long enough. Bad idea. But me being bull headed as i am i kept going. The second degree burns on my finger tips did kinda hurt. The top layer of skin was moving. But this was years ago. Young and dumb.

[TeflonG35]

Ive heard several good things about the Pulstar Pulse Plugs. They have dyno tested them in several magazines that i have read and the show significant gain in our motors. I know for sure that d-sport did an article about them with dyno evidence to back it up. The gains are somewhere between 5-10 hp. But they cost more. like $25 a plug.