No, you do not add additional oil.

The 10/10 glow fuel with gasoline mix that I came up with has about the right proportions of everything. It ends up at approximately 3% oil content (33 to 1), which is a touch rich but ok. It has about 3% nitro, which has been working fine in the engines we have tested so far and helps the idle and transition a bit. And it has somewhere around 30% methanol, which has proved enough to keep the glow plug lit without the battery connected.

If you mix with another type of glow fuel, you start throwing the proportions off. For example 20/20 glow fuel, obviously has more oil than the engine will need by double, and can cause carbon build up and other problems. It has more nitro, which may or may not be ok for a given engine. And finally, it has less methanol, which may prove to be a problem keeping the glow plug lit.

While everyone is obviously welcome to experiment, I recommend the proven mix for the best results. Also note that we use a four stroke glow plug for the most reliable operation.

AV8TOR