However, biodiesel produced from canola and rapeseed oil is superior to soy biodiesel. Especially due to the widely varying price fluctuations of soybeans. And because the feedstock (the oil produced from the fuel crop, such as soybeans, rapeseed or canola) to make biodiesel makes up about 80% of the cost for 100 % biodiesel, basic economics dictate that the feedstock be obtained from the least-cost source, which is going to be either canola or rapeseed.