Gonzo, this might help.......

The numbers and characters on the plugs, are the product number, wire thickness, and thermal range of the plug’s body. Example: The Novarossi C6TG (F) or (C)

§ Product: C (Candele)
§ Wire Thickness: 6
§ Plug Type: T (Turbo)
§ Plated: G (Gold)
§ Thermal Range: F (Fredda = Cold)) C (Calda = Hot)

The plugs with cold thermal range F(Fredda), have a body with thinner walls and shorter body, so they dissipate heat better and faster to the engine head.

How to select the proper plug, regardless of Nitro %

·When the ambient temperature is high, we have to use a plug with thicker wire.

·Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.

·With high humidity percentage we should use a Hot (C) thermal range plug.

·If we have high temperature and high humidity, we should use a plug with thick wire and a Hot(C) thermal range.

The best instrument to determine which Turbo Plug to use, is those weather panels they sell for Yachts, that have Temperature, Humidity and Barometric Pressure on them. Have it calibrated at your local weather station, and you’re ready like the Pros.
That is the key to success or failure tuning engines with Turbo Glow Plugs, because they are so sensitive to weather variations that is unbelievable.

Following is a selection chart for Novarossi Turbo Glow Plugs

Type Thermal Range Nitro% Temp.C° Humidity%
C5TGC Hot/hot wire 10-20 0-10 70-100
C6TGC Hot/average wire 10-20 10-16 70-100
C7TGC Hot/cold wire 20-30 16-25 70-100
C8TGC Hot/ultra cold wire 20-30 25-up 70-100
C5TGF Cold/hot wire 20-30 0-10 40-70
C6TGF Cold/average wire 20-30 10-15 40-70
C7TGF Cold/cold wire 20-up 16-25 40-70
C8TGF Cold/ultra cold wire 20-up 25-up 40-70


AFM