Have you ever heard of cars running on vegetable oil? Does that even sound possible? Well, it is, and some people have been using vegetable oil as an alternative to petrol. They usually make this switch in an attempt to be more environmentally friendly and also to be more economical. A lot of those people get the oil for their car for free from restaurants. Instead of throwing away the used cooking oil, they collect it for free, filter it carefully and then use it to run their cars.
However, one cannot just simply pour in the vegetable oil into the car and expect it to run perfectly. The engine of the car has to be readjusted to use the vegetable oil, hence a conversion system is incorporated into the car to allow its user to run the car efficiently using the vegetable oil.
There is a difference between vegetable oil used as fuel and biodiesel. Biodiesel is a type of fuel that comes from vegetable sources, most probably soy which is refined at a special facility. Various vehicles with diesel engines can run on biodiesel or a blend of biodiesel and petroleum diesel without having to make many modifications. On the other hand, the use of vegetable oil as a source of fuel for a vehicle is a different story.
Using a gasoline-powered engine would make it very hard to achieve combustion with vegetable oil because the fuel lines are not built to handle this kind of fuel, and that is why a diesel engine is needed for the use of vegetable oil.
As vegetable oil has a very high viscosity, an engine will find it difficult in atomizing the fuel completely when it is sprayed into the combustion chamber, this will result in a clogged engine. However, there is a way to make it easier to use the thick oil. Fuel injector nozzles with an extensive filtering system can be installed to the engine. This modification ensures that only clean fuel reaches the combustion chamber. If dirty cooking oil is used, then it must be filtered well before it is poured into the gas tank.
If you would like to see what it is like to use cooking oil as fuel for your car, check out this experiment: