Spark plug NGK or OEM BMW

I suggest buying a known high quality replacement, not being picky about the exact spec, and seeing if that makes a difference. At under $5 it's a minimal cost and effort. Based on the what this engine was likely copied from, I would pick a NGK BPR4ES or BPR5ES from a vendor that doesn't have a reputation for NGK counterfeits.

I removed the Champion plug and replaced it with an NGK and on the first pull it ran.

I use NGK Iridium's in my generators. People say I'm nuts for spending the 10.00 for one, but I never have problems starting on gas or propane which is what I use with Iridium's, and plus you'll probably never have to replace it either.

I just replaced the stock plug in my Champion inverter with a NGK and it runs significantly better. No more random misfires.

I threw the nasty plug away, installed the NGK plug and it now starts on the first pull and runs smoothly.

I have always had luck with the NGK iridium plugs.

Denso and NGK have fared better than Autolite in my vehicles in my experience.

I owned my cruze for 5 yrs and had no problems with the NGK iridium. I paired it with a coil pack I ripped out another cruze.

I recently put in NGK LKAR7BIX-11S (93501) and some cheap amazon coils. A coil failed and I just replaced it all to be sure.

Put in NGK ILKAR7B11 (4912) around 186k miles. I've burned so much oil and did a piston soak at 205k~. I scrubbed the tips with a wire brush but it didn't do much. Lots of carbon. I really don't notice a difference.

I’ve kept to stock plugs with stage 1. I tried the recommended “colder” plugs and they failed in less than 10k miles.