Which champion plugs to run?

[kawahonda]

RN9YC or RN12YC?

I'm running the 12s right now. I've been told that they are probably too hot for my area.

How do you chose between each? I've been told by a Ford guy to go with the RN9YCs, but I'm curious what you guys think.

[1 Wild R/T]

JMO but none of them...

[kawahonda]

I've been happy with my Champion 12's....just wondering if they're too hot.

[Racer57]

JMO but none of them...

Totally worthless comment unless you tell what you prefer.

[73_Cuda_4_Me]

If you pull a 12yc and the insulator is white, it's too hot (or running way lean)... if normal tan color, good to run...

IMHO...

I run 12yc and never had problem... tried autolites, and ended up switching back to the Champions...

[Solarguy]

I think it is a good rule of thumb to use the coldest plug you can that doesn't foul and the only way to determine that is to try them. 

[autoxcuda]

 I've had better luck with Autolites