Was wondering what is the best spark plug to use! Have the HD plugs on my 2007 ultra classic. Any info would b greatly appreciated!

 

Use the standard HD plug, resistance has to be at the right amount or it could affect ECM. Nothing measurable to be gained by other brands other than possible problems.

 

Ive used multiples of plug names in the past.. NGK, Champion, HD, Autolite, Bosch, ... including Copper, Platinum, Iridium & havent seen a difference in any of them. Perhaps theres a difference in a high HP dyno shoot out.

Currently I have the cooler HD V-Rod Plat plugs in & it runs just fine.

 

Thanks guys!!!

 

Me too.....went to a cooler plug when I was troubleshoot my pinging problem. Feel no ill effects whatsoever.