Mixing Your Own Fuel

Introduction To Mixing Fuel

Often a nitro user will want to mix more oil into their fuel. This has several benefits, such as improved lubrication and cooling. Also a fuel with a higher oil content, makes for a much easier to tune nitro powered RC car. Most engines are designed to be run on 14-18% oil content, which many fuels may fall short of. Most backyard bashers will be much better off with an oil content in the 17-18% range, as it will aid cooling and help promote longer engine life.

There are two basic types of oil you can add to your fuel mixture, castor and synthetic. Both have their advantages and disadvantages. Castor oil will retain it's lubricating abilities much longer than a synthetic oil will. However too much castor oil can leave a varnish-like coating on your engine's internals. This coating will ultimately result in an engine that runs hot no matter what you do with it.

Synthetic oils do not leave the varnish associated with castor oil. However, a synthetic oil will break down much easier than castor oil will. To alleviate this dilemma, many people mix castor and synthetic oil together so that you can get the benefits of both, but on a lesser scale since they are mixed. I myself use a 50/50 mix of the two oils, but everyone else has their own opinion of the perfect blend. As far as brands go, you have many to pick from. Just use a good quality oil, I myself use Klotz/SIG oils as shown in the pictures below. However there are many alternatives to choose from.

One other item you'll want to keep in mind as you mix your own fuel, is that as you add oil your nitro percentage will go down. Usually this is no big concern as you will really only drop a point or two at the most, but it is something to keep in mind. As you experiment a little you may find out later that you may want to start with a slightly higher percentage of nitro to offset the loss, especially with the lower percentages of nitro.

The next page contains a fuel/oil calculator that will help you calculate the amount of oil you need to add, to a certain amount of fuel, to bring it up to your desired percentage of oil. It tells you the total combined amount of oil you need to add, but it's up to you to decide how you want to blend your castor and synthetic.

Part One:	Introduction To Mixing Fuel
Part Two:	Fuel/Oil Calculator