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Free Fuel



Well, Nearly Free

Fuel can be purchased at the moment from oil manufacturers or a regional distributor.  Check your phone book under restaurant supplies.  In this case you will be using new oil so filtering is not required.  However if you are using used oil you will have to pre-filter it before you can use it.  That's right, I said USED oil.  Proper filtration is the key to operating a Greasecar reliably. There are many factors that dictate the quality of vegetable oil and a variety of processing methods to suit the different needs of Greasecar users. On this page we hope to give you several options for collection and filtration, remember: the more effort spent assembling a good filtration setup the less effort the job of filtering will be.

Though filtration process and equipment are important to ensure the cleanliness of your oil they are not the only factor. Choosing a good source of oil is equally important. If oil is heavily contaminated to begin with it will be that much harder to process for use in your vehicle. A good clean source of straight vegetable oil will mean much simpler collection and filtration which will translate to a happier driver and less onboard filter maintenance.

Though most oil sources can be used you will want to choose wisely because not all waste oil is created equal. Though any vegetable oil can be burned with a Greasecar conversion system the condition of the waste oil will vary depending on the policies of the oil source and how it is stored. We will try to address most of these variables below.

Finding an oil source is the first step to your petroleum independence. There are several common sources of oil for your diesel, selecting one is largely dependant on the quantity of oil you will need as well as your location. Storing oil can become a real inconvenience so you should find a source that suits your needs. The most common sources of free vegetable oil are:


bullet Restaurants
bullet Distributors
bullet Chip companies


Oil distributors

Large oil distributors may be able to provide competitive pricing on bulk new vegetable oils and often have an abundance of off-spec or dregs oil that is disposed of. This oil has not been used for cooking and generally requires very limited processing. These companies are few and far between but can provide several thousand gallons per month.

Snack food Companies

Snack food companies are also large producers of waste oil. Though the oil has been used for cooking it is often far cleaner and of a higher quality than that used by restaurants. There are many smaller snack food, chip companies around the country and supplying you with their oil can often lead to good P.R.


Restaurants are the most common source of waste vegetable oil will produce anywhere from 5 to over 50gallons a week. The quantity and quality of this oil is largely dependant on what they fry and how often they change their oil. The longer oil is used before it is replaced, the thicker and dirtier it can become. If a restaurant cooks heavily battered foods and replaces their oil only once a week chances are they are not going to produce very much and the oil that is produced will be very dirty. Another consideration in choosing an oil source is the type of oil they use. There are two main classifications for frying oil: Hydrogenated and non-hydrogenated (or "pure"). Hydrogenated oil is processed to be used for longer periods and is made up of larger oil molecules. This means that it will become thick and sometimes even solid at temperatures up to 100F. Non-Hydrogenated oils can remain pour able at temperatures below freezing. The reason this is important is because you will need to filter restaurant waste oil. Either type of oil can be burned in a modified diesel but collecting and filtering hydrogenated oil will be much more of a pain in your neck than the straight variety.

Besides oil type you must consider oil quality. Make sure that if the restaurant rinses their fryers with water after draining them that the oily water is kept separate from the oil that you are collecting. Also, if the oil or the storage container has a rancid odor or a foamy surface it is likely that it is contaminated with bacteria and should not be used.

The final considerations, which can be negotiated, are the methods of draining and storing waste oil that the restaurant uses. There are three common storage methods: dumpster, barrel or jugs/buckets.



A dumpster can hold several hundred gallons and will often have some sort of hatch covering its opening. Dumpsters, because of their volume can offer the benefit of settling meaning that when the container is full the first couple of feet of oil are often very clean and safe to collect and filter.


A barrel will usually be that familiar 55g drum and usually will not have a very secure lid. Because barrels are not covered well they often have rainwater and debris in them.


The last storage method is 4.5-5 gallon jugs or buckets. These are the containers that the fresh oil arrives in and fryers are often drained into them when quantities are small or space is an issue. The advantage to 4.5 gallon jugs is that you can usually see what is lurking at the bottom of them; water, food particles and fatty acids they are also very portable, weighing in at only 35lbs and having a volume of less than one cubic foot.

Making the deal

It is very important to conduct your dealings with a restaurant in a proper manner. I have heard many stories of people losing or being denied access to a restaurants waste because they do not approach the situation in a proper manner. A restaurant owner is concerned only with the workings of their place of business any inconvenience can jeopardize your access to their oil. Whether the problem is puddles of oil in their parking lot, delayed collection resulting in oil accumulating beyond their ability to store it or distraction of their employees. The board of health and appearance of their establishment will always be on their mind. You need to be organized and respectful, you may be collecting their oil for free but they are also providing you with a service. If they are producing more oil than you will need you should find someone to share the source or make some room at home to store the surplus. If there is a risk of spilling oil lay down some cardboard or carry some kitty litter or saw dust along to clean up the mess.

Once you have tracked down a good source of oil you need to reach some sort of agreement with the producer of the oil source, i.e.; the restaurant owner. Any arrangement is going to be dependant on the attitude and interest of the owner/manager. The manager/owner will probably only want to deal with one oil collector so you may be expected to provide your own container and pick up the oil every few weeks, so make sure you have an idea of how much you will be using.

When you approach the restaurant you will want to ask for the manager as you first contact person. Be friendly and though you may be saving the restaurant money don't act like you are doing them a favor. Even though no money may change hands you are going to be starting a business relationship with the oil source and you will want to appear as professional and organized as possible. It may be helpful to bring in a copy of this book or some other piece of information to help them understand what you intend to do and show that you have thought things through. Once the owner/manager agrees to give you their oil you will need to arrange a pickup schedule and storage situation so plan ahead. Most restaurants filter their oil each day to be reused until it is changed, some may even be willing to run the oil through a filter for you when they drain the warm oil. This would be ideal because the oil can flow right through a filter when it is hot. You may also be able to setup a storage drum behind the restaurant with a filter in the top to clean the warm oil as it is being poured in. Refer to the filtration design section with plans for this setup.

Once the arrangements have been made you are ready to build your storage and filtration setup and get started.

Collecting it

If you can filter, store and dispense the oil at the source you should not have to worry about collection but if you need to transport the oil there are some things to think about. Oil containers can be messy to you will want cardboard or tarps in your vehicle to place under the containers. You may also want to carry some paper towels, rags and work gloves to keep clean. If you plan on collecting larger quantities of oil you will probably want some sort of transfer pump and larger storage tank on board.

A 12V DC pump can be fitted to the vehicle, which will allow the user to pump oil from large storage containers to smaller containers that can be carried with you. This operation will be limited by oil viscosity and ambient temperature. Remember to always draw oil from just below the surface of large containers because water and debris will collect near the bottom.

If your oil source stores their oil in jugs or buckets a collection pump may not be necessary. This will also mean that the oil is less likely to have been exposed to bacteria and water contamination. But be aware that 35lb vegetable oil jugs are made of a thin plastic similar to that used for milk jugs, this material can easily puncture so it is not recommended to reuse containers for very long and they can melt if filled with hot oil.

Filtration solutions

Because oil filtration and collection is the main responsibility associated with driving a converted vehicle, you will want to be sure that you create the cleanest and most convenient method to suit your needs. Though it may be hard to believe, collection and filtration of waste oil can be a very simple and hassle free process if you put in the time to create a good system.
bullet Where is it gonna go?
There are three common places to locate your filtration equipment: at the source, at home or in your vehicle. Keeping your filtration at the source will enable you to avoid transportation, keep any mess in a back alley rather than your driveway and possibly avoid the need to heat your oil for filtration. Keeping your oil filtering and storage at home could added convenience and enable you to do more tinkering but many may find it an eyesore and if you are renting you may not make your landlord very happy. Onboard filtration is necessary when you are traveling and may be worth setting up for those situations but because your space is limited and you will want to keep your vehicle clean you will not be able to incorporate all of the feature available in a stationary setup. Once you decide where you will put your filtration equipment you can begin designing it.
Designing your system
bullet Choosing components
There are many different brands and styles of filters and pumps that you can choose from. Cost and availability will probably be deciding factors.
bullet Filters
There are two styles of filtration; gravity fed and inline. A coffee filter is an example of a gravity fed filter though coffee filter will probably be too small and flimsy for filtering oil. Restaurant supply companies offer conical fry oil filters that are very similar to coffee filters but made of heavier material and generally not as fine. These are usually available in boxes of 50 or more and have a stitched seam up one side. I recommend turning them inside out and doubling them up with the seams at opposite sides. Fry oil filters do a pretty good job but only filter to about 20 microns, they are great for a first stage filtration especially if you can do it at the source while the oil is warm. Bag filters are also an option and are available in many micron ratings. Unlike paper cone filters, which are disposable, bag filters can be washed and re-used many times. Bag filters are designed to be used inside canisters for inline filtration but can be utilized for gravity applications.

Inline filters require a pump to use. These are often in the form of a can or cartridge with wither a bowl holding an internal element or a spin on self contained canister. This type of filter is used for pretty much every from of fluid filtration from hydraulic oil, water. Though motor oil filters may seem like a good cheap source they should be avoided because they contain an internal pressure relief valve. This valve ensures that your engine is nor starved of oil when the filter becomes clogged. When used for filtering vegetable oil it will allow dirty oil to flow right through and you probably will not notice until your onboard filter clogs up.

bullet Pumps
There are a few considerations to choosing a transfer pump. You will be using this pump to move a viscous liquid and possibly to force it through a filter. Whenever a filter is thrown into play there will be a certain amount of back-pressure created that will place a strain on the pump, therefore this should be factored into pump selection. There are several varieties of pumps available including motor driven, hand operated and air driven pumps, as with everything else each has its benefits and drawbacks.

Motor driven fuel transfer pumps are available from fifty to several hundred dollars and are available in 12VDC and 110+ VAC varieties for onboard or stationary applications. The motor generally drives a turbine or diaphragm that is usually classified by GPM (gallons per minute) or PSI (pounds per square inch). The more viscous the fluid, the higher PSI it will generate so select a pump with a high pressure rating. If too much load is put on an motor driven pump it will be taken out on the motor eventually can burn it out so if you choose to use a motor driven pump choose it wisely.

Hand operated pumps are usually driven by a leaver or crank avoiding the risk of damaging the drive mechanism (which will be you). You will need to anchor the pump to something fairly solid, such as your storage tank so that you can apply proper force. Lever operated pumps will transfer your energy a bit better than a rotary pump, allowing you to use your weight. Make sure you spend at least $50 if buying one new, there are many cheap Chinese made pumps that will not stand the abuse they are going to take. This style of pump is very sturdy and practical but if you have the fear of developing Popeye-like biceps they may not be for you.

Air driven or pneumatic pumps can be safely used with viscous liquids with little risk of damage. Compressed air is forced into the drive mechanism to turn the pump any excess resistance is released by pressure sensitive blow-off valves. The primary limiting factor in regards to pneumatic pumps is their reliance on a air compressor to provide air pressure.

bullet Hoses
When choosing hoses to connect your pump and filters you will need to consider; temperature, aperture size and wall thickness. Garden hoses are common and cheap but will probably not tolerate heat and pressure as well as metal pipe or heavy walled rubber hose. Use threaded metal pipe whenever possible because it will handle pressure without giving offer secure connections. When flexibility is required 5/8-3/4 rubber coolant hose will do the trick being affordable and readily available. There are also synthetic plastic hoses available with ultimate chemical and temperature tolerances but with so many materials on the market it can be tough to choose the right one and many are very expensive.


Build instructions

The following are several filtration systems designed for various applications. A parts list for each is included but parts can be substituted using the guidelines laid out in the previous section in order to fit your specific needs and budget.
bullet Stationary home system
If you have space at your home or shop and more than one vehicle these are the plans for you. Having your fuel at home can be very advantageous offering convenience and accessibility. You will want a heated tank, which a clever person may be able to plumb into household hot water pipes, but for simplicity these plans will use an electric heater.
What you will need:
bullet 55gal steel or aluminum barrel
bullet Transfer pump
bullet Inline filter element
bullet Large funnel
bullet Coarse strainer
bullet 1440 electric hot water element
bullet 3 wire AC cable with 3 prong (grounded plug)
bullet 3/4 in ball valve
bullet 3/4 NPT threaded nipple
bullet 3/4 NPT lock nut
bullet two washers that will fit over your pipe nipple
bullet Rubber grommet or washers to fit over your pipe nipple
bullet indoor/outdoor thermometer
bullet At the restaurant
By setting up your filtration and storage at the restaurant you will have several benefits: keep potential mess away from home and no need for heated filtration. Because the restaurant will drain and dispose of their oil while it is still warm it will easily pass through a filter that will be installed in the oil container.
What you will need:
bullet 55 gal barrel
bullet Transfer pump
bullet Dispensing hose
bullet Dispensing nozzle
bullet Stainless steel mesh

The container will require some fabricated parts, which can be made by a welder or if you have more time than money can be made with some cheap available tools.

bullet Sheet metal
bullet Pop-rivet gun
bullet Pop-rivets
bullet Tin snips

bullet In the vehicle
For filtering on the go some compromises in speed may be experienced. The most straightforward portable filtration setup for the greasy traveler uses a simple pump and inline filter. With this onboard design you will be limited to non-hydrogenated oil and warmer weather but it is a must when on the road.
What you will need:
bullet 12VDC fuel transfer pump (Northern Tool # 360-B972 includes: pump, hoses, strainer and nozzle.)
bullet 3/4 in flexible hose
bullet Dispensing nozzle (Northern Tool # 15520-B972)
bullet Mesh suction strainer (Northern Tool # 4011-B972, will also need by barbed fitting)
bullet Inline 10 or 15 micron cartridge filter (Northern Tool # 170308-B972 or water filter from hardware store.)
bullet Two NPT street elbows
bullet One NPT pipe nipple
bullet Rubber pipe union (to fit over suction strainer)
These items can simply be assembled according to the diagram. You may choose to hard wire the pump to your electrical system which can be done with some 10gauge wire and crimp on fittings attached to your battery. Another cleaver trick that may be an option in some cases is to cut a hole in the trunk of the vehicle so that you can keep your suction hose outboard to avoid mess.


What continually blows my mind is that since the creation of the diesel engine we have had the opportunity to use vegetable oils for fuel and we have refused to do so.  What MADNESS!



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