[LifeofReiley]

I read a post somewhere in the last month stating 37BY plugs were Iridium. Anybody know about this fact or maybe saw the same post? Is this really true?

 

[Mel]

-37BY is the "reach" and "heat range" of the plug. It may or may not be iridium. I've been running -37BYs for many years, but I don't run iridium.

 

[LifeofReiley]

Answer

Hi Mel,

I just found the answer... 37BY's are not iridium, (S) plugs are. I'm running
37BY's on the bottom mag side and they work very well. I'm not spending $80.00 a plug that's for sure. Might add another LS EI.

http://www.aircraftspruce.com/catalog/eppages/champsprkplugs.php