I know it is a matter of personal taste or mental state but really , which brand do you think is better ? I've used NGK in my Beemers and my Jap bikes for years, but this is my first Harley (2004 Roadking) and I need to make sure I make the right decision. So , which one is better ?

 

I think I would defy you to evr really see the difference. Me- I use HD, then I know I am getting the right number, the right heat range, etc......MAybe just getting old and too lazy to do a cross reference..............LOL

BRUCE

 

As long as the plugs aren't crapping out on you, I doubt you would see the difference either. If your bike is so finely tuned with mods that the temperature of the spark is making a difference...you DA MAN!

Mac

 

Ive ran both in my hog and never noticed a change. It like the oil brand you use, its mostly preference.

 

In my personal Harleys, I like to use H-D Double Platinum. They last a very long time, without loss of performance.
On the same subject....
From my experience, the Screamin' Eagle twin electrode plugs (aka: Splitfire) are the worst plugs ever.

 

Thank you , gentlemen !

 

I usually run Autolite or NGK. Hd plugs are too expensive.

 

Try this.
http://www.nightrider.com/biketech/hdsparkplugs01.htm