RE: glow plug
The hotter a plug is rated the sooner it will ignite the fuel. Igniting the fuel sooner ensures more complete combustion , too soon and it wil detonate.
Generally run the coldest plug you can for maximum fuel efficiency since you can run slightly leaner on the high speed without melting the engine, but hot enough to maintain the idle. Too cold a plug will cause the idle to load up and flood out considering proper needle adjustment.
when you run more nitro you should use a colder plug.
Irun Merlin 2001 plugs in my volcano S30 and they work great with my 15% SIG Champion fuel.