Denso Long Life Iridium vs NGK Laser Iridium

[MaximaGuy]

Plugs are a difficult decision and since the job is intense, its best to get OEM.

Now if OEM manufacturer sources it from NGK or Denso is of less significance at that point.

Personally don't remember ever sticking in a non-OEM plug into my vehicles.

EOD it is a personal choice, its best to stay OEM since downstream components can get affected with an improper plug/burn rate.

 

[y_p_w]

Originally Posted By: MaximaGuy
Plugs are a difficult decision and since the job is intense, its best to get OEM.

Now if OEM manufacturer sources it from NGK or Denso is of less significance at that point.

Personally don't remember ever sticking in a non-OEM plug into my vehicles.

EOD it is a personal choice, its best to stay OEM since downstream components can get affected with an improper plug/burn rate.

Sure. I rather prefer some of the manufacturers that source from them and specify them by retail part numbers. If I really want an NGK Laser Platinum, I have the choice of getting the same plug cheaper at Pep Boys compared to the more expensive version that comes in a Honda box. I can buy a 4-pack of NGK PZFR6F-11 for about $40 at Pep Boys, but the local Honda dealer is listing them as going for $22.60 each (same price for NGK or Denso equivalents). The Denso is actually a lot cheaper from Amazon at less than $7 each while it's about $10 for the NGK.

There was a time when GM was buying plugs from NGK for their "100K tuneups" because they were some of the most durable on the market. However, the emissions sticker and owners manual only specified the AC part number that GM rebranded. I'm pretty sure that there was an exact NGK retail plug that was identical except for the label, but there wasn't necessarily any guarantee.

 

[PandaBear]

It's the calibration. OEM can spec any plug they want and calibrate to it. Aftermarket that has no OEM businesses have to guess instead of relying on test data. The plug can be good, but not the same as the OEM design or get feedback if test fail at corner cases.

For large volume models they may sell enough aftermarket to figure it out on their own, but for small volume vehicles / engines I'd stick with OEM.