They range from really high quality ones like avocado oil, cocoa butter, all the way down to maybe lower quality ones like palm oil and vegetable oil derivatives.
So, science came to the rescue with the magic of margarine, where hydrogen is added to vegetable oils, to make a solid known as partially-hydrogenated oil, which was supposed to be the healthier alternative to butter.
In 1912, he said: " The use of vegetable oils for engine fuels may seem insignificant today, but such oils may become, in the course of time, as important as petroleum."