What are the long term effects of using plain filtered used cooking oil in a diesel engine?

I saw this on Mythbusters. They filtered some used cooking oil, put it in a diesel engine, and got 30 mpg from the car. Sure, they proved it would ';work';, but could you keep the car functioning by simply using filtered used cooking oil as a fuel?What are the long term effects of using plain filtered used cooking oil in a diesel engine?
I've heard good and bad things about using this as well as biodiesel. Good- it is supposed to actually extend the life of the engine because it is an excellent lubricant. Bad- it can quickly clog your fuel filter and cannot be used in weather under about 45 degrees. Very Good- it is renewable and much cleaner fuel for the environmentWhat are the long term effects of using plain filtered used cooking oil in a diesel engine?
They don't have enough information to determine what the long term effects would be using alternative fuels. They can't tell or predict what effects it would have on the environment.
I would want to know whether or not the seals in the fuel injection system are compatible with the vegetable oil.





If the seals are not compatible with vegetable oil, they can break down. In that case, you would hve to replace the seals, which is not cheap.
The long term effect is that your fuel system will probably go away.
Vegetable oil may be a cleaner fuel for the environment, but diesel is not. Ever see the black smoke coming from a tractor trailer truck? That is diesel. Companies use 25% more oil to produce diesel than gasoline. Look it up. The only reason people like diesel is because you can get more life out of your engine and maybe a little better mpg. 30mpg, I get that in my volvo s40.