Recommendation: When looking for plugs on these vehicles, I would recommend looking at 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 your year, engine, etc I would recommend
NGK Iridium IX® Spark Plugs as others have. Most of the V8 models have NGK OE, others have a mix.
Like 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 is due to changes in fuels being pumped today.
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 (20ftlbs for us US based owners) (Note: head should be cool enough to hold your hand on it)
Lightly lube plug threads with copper- based anti-sieze compound (IF not on plug already)
Replace your Coil on Plug Boots (if equipped) see the two types of coils images below. Part #2 on the right image. They just twist and pull off.
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2005 X5 4.8IS
The
Blue ones are always FASTER....
Current Garage:
2005 X5 4.8is
2002 M5 TiSilver
2003 525iT
1998 528i
Former Garage Stable Highlights
2004 325XiT Sport
1973 De Tomaso Pantera, L Model
1970 Dodge Challenger T/A 4 sp Alpine White
1970 Dodge Challenger T/A 4 sp GoManGo Green
1971 Dart Sport, “Dart Light” package
1969 Road Runner 383
1968 Ply Barracuda 340S FB Sea-foam Green