Spark plug OEM BMW or AC DELCO

I'd use the original equipment AC Delco plug. Rockauto has them for $6.31 each, with a $3 per plug rebate offered.

At least with double iridium ACDELCO on the c5. It’s 100k intervals.

AC Delco double platinum spark plugs belong in that engine.

I use them. Just replaced a set after they'd lasted 90,000 miles, only to rule out a very very tiny misfire count issue I've noticed lately. I might get a coil pack now, but those original plugs surely would have lasted longer (they say they should last for 100k).

I had similar problems with mine until I tried stock F80 M3 plugs. Mfg #12120039634KT1. Mine was 07 N54 FBO.

I replaced them with AC Delco 14 Platinums, and it seems to be running better.

Just did mine with ac Delco, gapped them in advance and running great!

I bought six ac delco spark plugs from Rockauto and half were made in France and half were made in the US. There are very slight differences like the diameter of the electrode and how deep the plug is on the end that goes into the cylinder. Even one of the US plugs is different from the other two.

ditch the delco plugs, they are trash. And delcos are shit plugs.

My 6.0 never ran right unless I used AC Delco. And specifically whatever the current equivalent part number is to what the manual says.