I'm about to replace my plugs (2009 R56 Base) and in looking for the correct gap and torque, I see a variety of numbers, which I find odd. I'm a long time MG owner and this stuff is settled science.

This is what I find to be correct for my Beru Z336 (12 ZR-6 SP2) after sifting through the chaff.

Tightening Torque: 23+3 Nm or 17+2 ft-lb
Gap: 1.0mm or 0.039"


I also see that it's recommended NOT to use Anti seize on the plugs as it can affect electrical ground. Anti seize will also affect torque.

I see noted in a number of sources that the plugs are "pre gapped" and/or "non adjustable". This seems just ridiculous. Of course, the plugs are adjustable and why not check the gap to see if it's correct??!!

Of course, you need to take care not to bend or damage the electrode wire.

 

I've been really happy with NGK --- https://ngksparkplugs.com/en/part-finder

Here's their suggestions, and for torque settings, check out --- https://www.newtis.info/tisv2/a/en/