Model aircraft fuel is primarily comprised of
Methanol and oil. Methanol is the "fuel" and the oil is simply
a lubricant. Many fuels also contain
Nitromethane which is a power
Additionally there may be other ingredients in the fuel such
as detergents or agents to help the nitro mix into the alcohol.
Traditionally the oil in fuel has been Castor oil.
Castor will tolerate very
lean mixes well and help protect your engine.
However, castor is more difficult to clean from the exterior of the model.
100% synthetic oil fuel has become very popular.
Unfortunately the oil content is much less than it used to be. Clarence
Lee advocates adding additional castor oil (approximately two ounces) to each
gallon of fuel. The problem is that the lower content, 100% synthetic oil
fuels are great until you have a lean run and toast your engine.
I personally use fuel that has some castor in it and never use 100% synthetic.
I do not mind losing a little top-end performance to give myself a safety margin.
If you are a performance freak and do not mind sinking a lot of money into engine
repairs then by all means use high-nitro, 100% synthetic fuel and
burn holes in the sky and the tops of your pistons.
I like nitromethane to a point. It helps with
idle and adds a margin of power but it is expensive and over time you will
save money by simply using a larger engine if you want additional power. I
use 10-15% nitro fuel that gives a good balance for sport flying.
I recommend that you use fuel with a minimum of 16%
- 18% castor/synthetic blend
oil for general flying. For breaking in your engine I
recommend 5-10% nitro, 100% castor oil fuel for ringed engines. For
type engines use the same fuel you will fly with unless you plan to use
low oil, high nitro fuel for flying. In this case break in your engine with higher oil
and less nitro before switching to "performance" fuel.
Any fuel from the major manufacturers will work well and will not harm your
engine if you select the correct fuel. I honestly can not tell a difference
between comparable fuels from any manufacturer's. I never use store brand
I've used all the following fuels and have had no problems with any of them:
- Cool Power
- Wildcat (my current fuel)