Grease for diesel


I heard an old boy tellin’ me that you can use old restaurant grease in your diesel and save on fuel. He said if you strain it through a really fine screen it won’t hurt anything. Is this true? Or is it an old wives tale.


That’s DIY biodiesel. And yes, it works.


Well, sorta. There is a difference between using waste vegetable oil (WVO) and bio-diesel (either commercial or homemade). Bio-diesel undergoes significantly more processing than WVO, which is normally just filtered and de-watered prior to use. There is a lively debate as to the wisdom of using WVO in diesel engines. Some folks use it mixed with diesel fuel or kerosine, some mix it with gasoline, some have installed “two-tank” systems (including heaters) in their cars, and some (like me) wouldn’t touch it. Do an internet search, you will find hours of reading on the subject (and little agreement).


With significant modifications to the fuel system, it is possible to run a diesel engine using WVO. However, you have to do a good amount of purification of the stuff before it’s suitable to be used.

I have no idea if it’s cost-effective, efficient, useful, a smart thing to do, or anything. There’s stuff all over the internet about it, so read up.


Greasels…Google “biodiesel” You can’t just pour restaurant grease in your fuel tank…A little refining is necessary first…


Well I would want to do some filtering and cleaning first. There are some other issues as well, but frankly it is not much more than that.


Cooking fats and oils must be broken down first before they can be used a fuel in a diesel engine…


If you have a $2000 car, maybe an old Rabbit or MB, then making your own fuel from waste veggie oil can be a good way to save money.

Try pouring poor quality WVO fuel in a newer diesel car, and this could be the quickest way to turn a $20,000 car into an $8,000 car.




Yea, I was thinking back a few years to my early diesel Rabbit. The process was far less effort than what I understand it is today. Not that it is impossible to back yard process the stuff to today’s standards.

I think I will leave all that work to the other guys.  I'll continue to get my diesel from the pump.