Glow plug recommendations

[Gee]

Okay, I know there not a lot of Nitro guys hanging out at RCm, but before I go through the registration at a nitro forum to ask one question I though you all deserved a second chance. I'm betting some of you have experienced the nitro side and that why you are running electic now.

I see there are three different ranges for the glow plugs. Hot, med, cold. Is this for the type of fuel being used? Are the glow plugs based on the fuel being used or the size of engine that you have? Meaning can I run the same type of plug in the engines above if I am running the same fuel in them?