CARS,

The 7.5 engine will prefer 15% nitro, 18% oil; 22% is too much oil. The D/F community seems to think that the extra oil protects the engine against a lean needle setting, when in fact it just burns off at the operating temps of the engine. A gallon is always 128 oz. and when the oil is increased from 18%-22%, something else went away. Methanol? Nitro? The extra oil actually provides for poorer combustion and reduces the BTU energy of the fuel. By adding 1 oz. of turbine engine oil, you add 0.08% lubricant (which doesn't burn off at operating temps) and it doesn't dilute the methanol or the nitro, nor does it destroy the BTU energy of combustion. You'll find the turbine engine oil at the fuel point at a local airport--about $12.00/qt. It will give you about 25 gallons worth of fuel additive. I actually use it in all my glow fuel--4-stroke, sport, etc.

Best regards,
Larry Wolfe
[email protected]