when the 4th gens were relatively new, PFR56 plugs by NGK were considered mandatory albeit very expensive. Is it ok now to go with iridiums or something cheaper?

 

for as often as you have to change plugs i wouldnt cheap out

 

I think the model # you listed is incorrect. The OE replacement is the PFR5G-11
Okay, here is a list of suitable replacement plugs.

• Standard: BKR5ES-11 (basic plug - classic electrode design)
• V-Power: BKR5E-11 (45 degree V-grooved electrode - improved ignitability over standard plug)
• G-Power: BKR5EGP (fine-tip platinum alloy - not pure platinum/economical version)
• Iridium IX: BKR5EIX-11 (Iridium fine-tip)
• Laser Platinum: PFR5G-11 (OE replacement part. Laser welded-platinum tip)

Out of the first three economy plugs, I would choose between the 2nd & 3rd.
I currently have the G-Power's on our '95, good plugs, no complaints.

The (OE) Laser Platinum I have on my '99 recently and they're great. They should last for as long as I plan to have the car!

The Iridium IX came with a '95 I briefly drove, no complaints there either and others have also noted good results.

 

The NGK BKR5E-11 are also known as copper plugs. That's what I use in my NA Maxima and my boosted Maximas (except they're one step colder)

OEM Part number is 22401 - 50Y05

 

+1 Both of my 4th gens love the BKR5E-11s. I get them for about $2 each

Sent from my Z998 using Maxima

 

do not cheap out on spark plugs, or u will result in some crappy things when you drive the car.. never be soo cheap on parts.

 

If you're referring to the $2.xx coppers, then your statement couldn't be farther from the truth.

 

I've tried the really expensive oem laser platinum and cheap coppers. Buy the v-power. The other materials just last longer. Platinum and now iridium. The copper works better just wears out faster but our plugs are easy to change.

 

Economical performance and improved ignitability over standard NGK Spark Plugs original equipment manufacturer and racer approved.

- Lowers ignition system voltage requirements <-- Good for older coil packs.
- Greater ignitability and performance over conventional spark plugs
- Trivalent Metal Plating has superior anti-corrosion and anti-seizing properties
- Increased fuel economy and lower emissions
- Highly durable against electrical and chemical wear
- Good performance spark plug

 

Gotta say, my car really does like the basic copper plugs too!
At $2 each, change them every 25K miles and you're way ahead of the game!

 

x10^e10