I am debating whether to get the DENSO Iridium Long Life Spark Plugs or NGK Laser iridium spark plugs for my 12 M37X. The price difference is about $80. Please advise.

You are trying to hard. Any Iridium spark plug will do.

NGK ONLY on anything that Nissan makes. Never anything else. I'm not kidding. Many horror stories of people using Bosch, etc.

I agree. Too many stories of non-NGK plugs having to be removed and replaced with NGKs. Belive me, you do not want to pay for this service or waste all those hours doing this yourself twice.

OEM for our engines is Denso, so that is what I have been using, so far no problems at all.

I have experience with NGK's as well, on my Z (they are OEM for that engine), and have not had any problems either. If you are not doing any tuning or high performance build OEM plugs will be fine, I would jump up to Iridiums though

I have never seen a Nissan/Infiniti use anything BUT NGK...for decades. Maybe the brand new cars are different, but I have Nissan knowledge going back to the model year 1997 (my first Maxima) and I've had 3 cars (99 Maxima, 07 M35x and now my 11 M56x) and all of them are NGK.

EDIT: I did some digging and turns out the M37/Q70 3.7 uses Denso while the M56/Q70 5.6 uses NGK. Color me edumacated. Did not hear or know that Nissan started using anything other that NGK.

Here is a screen shot. Page 3/4 of the FWD section of the 2011 Infiniti M Factory Service Manual.

I just had my 90k service done, and spark plugs. Shop used Denso Iridium

I wonder why they make the V8 M go NGK and the V6 Denso and why they can't be interchangeable.

which ngk part number for the plugs for m37?

I need to do this also.

I'll be useing the NGK DILKAR7B11 (1406), Rockauto has the cheapest price $15.21ea $128.67 (8) to my house. Cheaper than EBay or Amazon.

Andy

for m 37? ^

this not too bad

https://www.amazon.com/Tune-Plugs-Filte ... R7B11+1406