While there are many reported advantages for the use of biodiesel fuels, there are also many disadvantages, with numerous problems or faults being reported by users. This is in addition to the problem of the cost of using biodiesel due to it being so much more expensive than regular petroleum diesel.

One of the main problems seems to be the use of additional land being taken up simply to grow the extra crops required. To make biodiesel fuel on such a large scale obviously requires growing the crops on a large scale too. While some countries have more arable land available for this task, there are smaller countries that simply do not have the amount of land required readily available. In some countries in Europe, almost all the arable cropland would be consumed with even a modest use of biodiesel. If the trend is followed and more and more of the smaller countries decided to manufacture biodiesel, it could turn out that instead of those countries exporting their food produce they would actually have to start importing it. This would have a catastrophic impact on those countries economy.

Biodiesel fuels are also not as suitable for using in low temperatures as petroleum diesel is. Fuel has a “cloud point” which is the temperature at which a fuel starts to look cloudy. This is an indicator that wax crystals have started to form within the fuel. If this happens then the chances are that filters and fuel lines in the vehicles fuel system have become clogged. If the temperature drops even lower, the fuel can become a gel which is impossible to pump. If the fuel cannot flow then it has reached the “pour point” temperature. Because the pour points and cloud temperatures are higher for biodiesel than they are for petroleum diesel, the performance is significantly worse for biodiesels in colder weather or cold weather countries.

A rise in food prices, not meeting environmental standards, being responsible for natural habitats and rainforests being destroyed, are just some of the things biodiesel fuels and their manufacturers have been blamed for and accused of. It has been alleged that numerous suppliers of biofuel to the United Kingdom were not giving full reports on their fuel source sustainability, causing concerns and demands for the situation to be carefully monitored.

There are also concerns about the production of carbon emissions when using Biodiesel Fuels. Numerous studies have been carried out in order to analyze biofuels and their carbon footprints. It has been shown that even though biofuels are cleaner to burn, there are very strong pointers that the fuel production process itself, has very bad carbon emissions. This also includes the fuel production plants and the machinery used in the crop cultivation. Another problem could be the price of staple foods being inflated due to crops such as corn being planted and cultivated for the sole reason for using it to make biofuels. The irrigation of these extra crops could also put an untold strain on water supplies due to the huge quantities of water needed.