MCT oil is typically fractionated coconut oil(Not sure if any other oils are used.) Some suggest that it is much less likely to be deposited as fat tissue and can be used by the body as an energy source, much like carbohydrates. I've used it myself, but the only time I think it might be useful is on a very low-carb(CKD, TKD, etc) diet. I usually take 1 tbsp before workouts when on such a diet and it gives me a bit more energy. Mixing it with Ultra Fuel would be both pointless and I suspect you end up with globs of oil sitting on the top of your drink. Not very appealing. Mixing it with protein powder in a blender does work though.