First of all, yes i have read all the other threads on spark plugs. And yes maybe I missed one. But I would like to know which is the best spark plug for a '03. Some people are going to a plug which is one step colder. Has this helped in the pinging of the 3.5? If it has which of the NGK plugs are they using? From most of the threads that I read the NGK Iridium are the best plugs to use in our engines. Which part number should I ask for when i buy the plugs. Sorry if this is a repeat on several threads, but it would be nice if we could put it in the stickies. Best type of plug for which application would be nice.

 

I'm driving the 3.0 and when I replaced the plugs a couple weeks ago, after a ton of researching, I went with Iridium IX. I've also heard of the colder plug to fix the pinging, but only about 50% success rate.

For 03 max Stock #4469 Part #LFR5AIX-11...the part# for the colder plug would be LFR6AIX-11, stock #6619

Just a little fyi, definitely check the gaps before installing. They should be 0.044...when I checked, they varied between .040-.043 so they needed to be corrected.

 

If you are having pinging issues, you need to be looking at the knock sensor or if you are using regular fuel - step up to the 92 octane Nissan is calling for. The purpose of the knock sensor is to adjust the timing should pinging occur. My personal choice in plugs are NGK Laser Iridums.

 

What brand would the 03 Max Stock be?

Can you buy them elsewhere besides the dealer? I would like to save some money.

Thanks!

 

Nissan used NGK spark plugs in the Max. Part number PLFR5A-11 (stock# 6240). They can be purchased form any parts store the sells NGK. Yes, they are expensive. But keep in mind that you would have replaced 3 to 4 sets of the old copper plugs by now.

 

Go to the part store. you can go the the ngk web site and find out the part number for the plug you want. goto autozone or advance auto parts web site, then look up the park plug and find out that stores part number ( I believe advanced uses the ngk part number) then write that and use it when you go in (just to save time and confusion).

plats I bought from advance was about $6/plug

 

If buying Platinum (Pt) plugs, be sure to get the one with double Pt. (i.e. Pt on both electrodes). Here's info. for your car from Advance Auto Parts website: Part No. 6240, NGK Laser series Platinum Plug, PLFR5A-11 This is the OEM plug.

 

I wanted to buy the OEM NGK plugs, but I ended up getting the Champion Double Platinum ones instead because I got them for free.

I noticed no difference and the car runs great after installing them.

Champion #7975 is the part number. OEM spec, gap of 0.044

I would still go with the NGK's if possible though.

 

I needed new plugs for my 2000 and saw an episode of Horse Power TV where they put E3 spark plugs in a small block Chevy engine that was mounted in a dyno (not in a car). They dyno'd the engine with the stock plugs and then changed to E3. The E3 produced more horsepower and used less fuel.

So I bought a set off amazon for 5.95 each, shipped and put them in. I think the car has more zip to it. The E3.48 plug is the E3 model for the NGK PLFR5A-11. There is no hotter/colder options. My car pinged with the NGKs and it pings with the E3s.

 

No spark plug is going to give you extra HP or mileage with todays ignition firing and control system, assuming the plugs being replaced are firing. Naturally if a plug isn't firing, the installation of new plugs will be instantly recognized.
Stick with the stock plugs and you'll be good to go for anohter 100,000 miles or more. If you don't mind changing them, go with the less expensive plug designated for your vehicle.

Always like to have backup information available, so here's the lowdown from NGK:

Q: How much of a performance improvement can I expect from changing plugs?

A: A common misconception is that changing spark plugs will result in a large power increase. In most cases, removing even seriously worn out spark plugs will only result in very modest power gains, typically about 1-2% of total engine output. This could be even less for computer-controlled vehicles, primarily because most newer vehicles have more powerful ignition systems and the vehicle's computer can make adjustments so that vehicle operation seems smoother and more seamless.

Many people think that simply supplying more spark to the firing tip can and will combust more fuel. What they don't understand is that most newer cars' engines are so efficient that they are already burning all of the available fuel. Simply adding more spark voltage can't burn more fuel because there is no more fuel to burn.

When a stock or near-stock engine is given a fresh set of spark plugs, peak efficiency is restored. The power gains that come from this restored state of tune are usually minimal. Any company that tells you that their spark plug will provide significant gains in power in a stock or near-stock engine is making blanket statements that may not be supportable.

 

Agreed. Its pretty much the fuel ignites or it doesn't. I can't see how a hotter or bigger spark can ignite more fuel.