Recommended spark plugs for N-62

[X53Jay4.8is]

Originally Posted by StephenVA

Plug Recommendation:
When looking for plugs on these vehicles, I would recommend looking at the plug manufacture's website for what is the latest information: Example: NGK Spark Plugs USA. Technology has moved on since our vehicles were designed, engineered and screwed/bolted/welded together.

Without knowing everyone's year, engine, etc, I would recommend NGK Iridium IX® Spark Plugs over all others as owners have posted before. Most of the V8 models have NGK OE, others have a mix.

Like many others, I tried the two and four prong Bosch plugs and replaced them with the fine wire Iridium NGK plugs, due to poor idle, Tip-in acceleration response, etc. My 2005 4.8is had NGK OE fine wire but not the better Iridium ones. Having worked for one of the plug manufactures earlier in my career, I would say finding the right plug characteristics for your vehicle is more important than "what came in OE". Most of that thought is due to changes in fuels being pumped today. Summer gas, winter gas, ethanol, etc.

Note: Check the plug manufacturer's website for all applications not the distributors (resellers) as there are MANY errors on their sites.

TORQUE SPECS:
As mentioned, 23 nm /18ft-lb. Note: torque can be + or - 3nm. Multiple people have had the plugs back out if not torque to the higher number (20-ftlbs for us US based owners) (Note: head should be cool enough to hold your hand on it) It has been posted before that some owners experienced the plugs backing out of the head when using 18-Ftlbs (Me personally). Use the higher setting to not experience that on a long trip.
Lightly lube plug threads with copper- based anti-sieze compound (IF not on plug already- Note: some plug manufacturers have anti-seize on the threads already in the box).

Plug Gaps- There is no spec for multi prong plugs. Fine wire plugs use the same spec as posted .044"

Coil on Plug Boots: (if equipped) see the two types of coils images below. See Part #2 on the image. They just twist and pull off. These are really just short plug wires with the same deterioration that wires have. They will build up resistance over time to the point that the voltage leaving the coil can not over come the resistance and causes a miss fire. Recommended replacement is the same with plug wires, test resistance or toss away at plug change time 60/80,000K or every 5 years. Cheap insurance.

Attached Images of the two main types of coils and the two types of coil boots (Bosch and Bremi) as found in our X5s. The newer style "Clip on" coils do not have replaceable boots. A dab of Dielectric grease on the plug end will seal from moisture and that leaking oil from your valve cover gaskets

Steven is there really much difference in performance of the NGK Platinum spark plug vs the Iridium version spark plug?

[StephenVA]

Originally Posted by X53Jay4.8is

Stephen, is there really much difference in performance of the NGK Platinum spark plug vs the Iridium version spark plug?

There are three plugs recommended for the X5 4.8is from NGK.

OE NGK ZFR6FH-11, Stock number 4294. Iridium 0.8 center electrode with a platinum ground electrode plug. Factory gap of 0.044 inches
G-Power NGK ZFR6FGP, Stock number 7100. Platinum center electrode (un marked size) with a Nickel core side electrode. Factory gap at 0.040.
Iridium IX NGK ZFR6FIX, Stock number 6441 Iridium 0.6 center electrode Tip (copper core) with a cut back and tapered platinum ground electrode plug. Factory gap of 0.044 inches.

The big difference between the OE plug and the IX is the additional engineering and trimming steps to provide better anti-fouling, easier cold starts, better tip in acceleration, and the shells are coated with anti-corrosive and anti–seizing materials.

The recommendation is always go with the plug that will provide the best performance over the widest range of driving. In our applications I would go with the NGK Iridium IX plugs every time. Will the smaller center electrode wear faster? Yes, in a lab. You will get 60K out of them easy.

I remember replacing plugs after every race, every 5-15K for street cars, as they fouled and got coated with all types of materials that were present in old leaded fuels. Not the case now days. Plugs are cheap and easy to install. The OE plug use of technology is way ahead of where it was when I worked at Champion Spark Plugs. The technology that was once used exclusively in Top Fuel, Indy Cars & F1 racing is now at the commercial and OE levels. When I worked with race teams, race shops, etc, our manufacturing cost on Race plugs was approx. $14 a plug. Now retail is over the counter at under $8 for the same technology.

I personally played with most of the major brands and can tell you everyone makes great plugs. Some are more turned for a particular application than others.

I could go on and on over the advantages of precious metal tipped plugs over nickel ones, but I think everyone gets it now days. Long life, etc, etc.
Helpful?

[StephenVA]

Oh, One more tip.

GAP THE DAMN PLUG BEFORE SCREWING IT IN.
Setting: 0.044, use a gaping tool, do not guess.