Couple years ago, I found and printed a chart from NGK describing what each character in their part number means. For the purposes of this thread, plug gap, the '07 R56 OEM number of ILZKBR7A-8G, the "8" describes plug gap, and translates to 0.8mm (.032"). If we're supposed to be using the "preset" gap, we're probably expected to use the intended 0.8mm.

Quick summary of gap ID's ---
none= 0.8 - 0.9mm
-6=0.6mm
-7=0.7mm
-8=0.8mm
-9=0.9mm
-10=1.0mm
-11=1.1mm
-13=1.3mm
-14=1.4mm
-15=1.5mm
There is no "-12" listed

Similar process for heat range --- OEM is range "7". NGK 1422 (ILKR8E6) is one range colder (8), and gap is "preset" at 0.6mm. As previously mentioned, optimum plug gaps vary widely. Trial and error, or the ever popular butt dyno works pretty good to decide your best gap setting.

I can't find the same chart again, so can't link to it. However, a search thru NGK's web site (maybe NGK USA) will yield specs on any of their plugs.

As for the NGK1422 ⅝" plug wrench, I found one from a Snap-On truck that fits without any grinding. 'Course it cost more than the set of 4 plugs, but they are available.

 

Thanks - that's great info to add to this thread, and I hope it helps others. I went with 7MM, and that worked fine - the car ran like a watch. At 58K miles the plugs that came out had about 2X the factory gap, so those plugs were WELL past their prime time.

My recommendation to others with the Cooper S model is to change plugs to 30K intervals. These clearly had been in the car longer than necessary. The symptom was missing at higher speeds (40 MPH and up), probably due to lack of ability to keep up with the higher RPM.

 

OK all you R56 NON Turbo owners. Well at least the 2010 model anyway. I just spoke with NGK and the PLZKBR7A-G plugs have been discontinued, and the new part number is
PLZKBR7B8DG. And per NGK the gap is .032 or .8 mm. So if you have any questions about gaps or plugs, my recommendation is to contact the spark plug manufacturer. They know more than any dealership I have spoken with.

Good Luck.

Howie

 

see here for BOSCH: https://www.northamericanmotoring.co...ml#post4298145

 

I purchased the Delphi/BERU tune up kit put together by ECS Tuning along with the park plug socket for my 2012 Clubman S with JCW tuning.
I live in Ohio so I received everything within a few days.
Yes, it's an R55 but this still applies to the R56.
The plug gap was .7mm on all plugs right from the box (yes I did check).
PUMPKINHEAD is back to purring like a lion.
Thanks ECS Tuning for setting me up right the first time.
Not to mention your prices couldn't be touched anywhere else.

 

I default to ECS unless its less than $50 and I need to pay shipping at which point its Amazon. ECS never sends the wrong parts.

 

what part of Ohio are you in, I’m in Cincinnati.

 

Hello Cincinnati, I'm from Streetsboro, south east of Cleveland.

 

Sunday I will be up in Cuyahoga falls on Sunday picking up a new seat for mine, and helping install a RSB.