So I just replaced my plugs and coils on my E63 M6, and response and power seem improved a small bit. I went for the NGK Ruthenium spark plugs after reading a few reviews here and there that said they were real good. But I cannot necessarily attribute the improvements to just the plugs or the coils since I had just gotten a misfire code/limp mode prior. And as well, my plug on cylinder 5 was partly broken when I pulled it. The misfire code was for cylinder 6, ironically, and so since I had been wanting to do all the plugs and coils anyway (never done them on the car yet)- I went ahead and did them all at once and reset the service monitor for them.
But darnit this car is running better than ever since I've owned it (about 3 years). Smooth as can be. Still got a slight rough cold start idle, but still better than before the plug/coil change. After reading here, I can guess what that is. And that is next, as I can. But the question is, anyone changed just their plugs to the Rutheniums and noticed any difference? If not, you might try them. Pretty sweet I think. But not sure if that's what caused the improvement on their own.
But darnit this car is running better than ever since I've owned it (about 3 years). Smooth as can be. Still got a slight rough cold start idle, but still better than before the plug/coil change. After reading here, I can guess what that is. And that is next, as I can. But the question is, anyone changed just their plugs to the Rutheniums and noticed any difference? If not, you might try them. Pretty sweet I think. But not sure if that's what caused the improvement on their own.
