Spark plugs
Seasoned HDF Member
Joined: Oct 2006
Posts: 5,977
Likes: 85
From: Nevada
Autolites for $1.50 or NGK for a bit more. Both work fine and do not upset the anti knock feature as noted above.
I now have the NGK iridiums but see no difference other than longer life.
I now have the NGK iridiums but see no difference other than longer life.
Extreme HDF Member
Joined: Jun 2011
Posts: 10,216
Likes: 224
From: Glendale AZ
Road Warrior
Joined: Jul 2009
Posts: 1,979
Likes: 2
From: Northern Colorado
What don't you like about OEM plugs?
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Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
Autolite 4163 (one step colder) or 4164 (stock heat range) work fine and are only $1.50 each. The only downside to these is the screw-in plug at the top, which in my experience will unscrew on its own in time. I put a very small drop of red Locktite on the threads, making sure to cover only a small area, which keeps it in place. This is a direct electrical connection so you wouldn't want to separate the metal-to-metal contact very much by using too much Locktite.
Advanced
Joined: Jan 2010
Posts: 77
Likes: 0
From: Los Angeles, CA
Iridium plugs
Over 10,000 miles on NGK DCPR7EIX IX Iridium Spark Plugs, and they look almost new. Iridium has an extremely high melting point, so they seem to hold up very well in our hot air cooled engines. Be careful adjusting the gap, as the tip is allegedly brittle. About $7 each from Amazon.com.