Living with WVO, by P.G.

It has been said that necessity is the mother of invention. Needing fuel for their war machine lead Germany to invent and perfect the diesel engine. It was designed to run efficiently on vegetable oil, and they do to this day.

Circumstances forced me to make a move from my East Texas home to the deep Southwest. It was a slow, long process of gradually moving my stuff and my wife to a new homestead. I commuted from Nevada to East Texas for almost three years, at least monthly. Growing up farming, ranching, and trucking, I had a lifetime of experience with diesels, how they work, and what it takes to keep them running.

Experience Running Waste Vegetable Oil Fuel

It was the days of $4.00 a gallon fuel that set me on the veggie trail. Now, after twelve years of experience running waste vegetable oil (WVO) as fuel, I have learned a few things, which I will now share with you.

I have run Mercedes, VW, GM 6.2, Cat 9L, Ford 6.9/7.3, Ford Backhoe, Kubota tractor, and Gensets, China diesel, some NA, and some turbo. There is no difference on a very cheap and easy to do system.

My Diesels on WVO

I have Mercedes 240D and 300TD engines that run on WVO. I had a bus with a 9 liter cat v8 that I used to commute back and forth in, serve as a place to sleep, and for hauling stuff from Texas to Nevada. A 1982 3/4 ton Chevy 6.2 did well on WVO. I setup a 1991 F250, 7.3 Turbo with no problems. Also, I had a 1981 VW pickup diesel. My 1984 F250 6.9 NA pulls a four horse trailer with 120 gallon tank in the bed, and another 1984 F350 6.9 NA with 12 ft box and none miss a lick. Beyond those, I have a Ford diesel backhoe, Kubota genset, China diesel genest, Kubota utility tractor, and my new truck, 1988 F350 dually crew, 7.3 turbo to haul my gooseneck trailers for my stuff, and my new project is my school bus, 8.2 Detroit turbo, 5 spd/2 spd axle as my new motor home. Obviously, I like diesels, and they all do great on WVO.

Purge With Diesel

I always run a dual fuel system starting on diesel using engine coolant to preheat WVO and switch to WVO at 100 plus degrees F. When I shut down for the day, I switch back to diesel to purge the system of WVO. Some folks don’t purge, but I just don’t want WVO left in my pump or injectors for any length of time.

Where WVO Comes From in Volume

Restaurants are where WVO comes from in volume. I have no advice on collecting. Live and learn. I collect 800 to 900 gallons at a time in 55 gallon barrels. It takes me about four hours to collect, and then about two weeks to get the WVO ready for my diesels.


I transfer WVO from my hauling barrels that are heavy and in my trailer into 55 gal barrels in my storage area. I only put 40 to 45 gallons in each barrel. I top off the barrels with water! Sounds crazy? Ya, maybe, but my ’81 240d has over 50,000 miles on WVO with no problems. I then use a pump, suction on bottom of barrel, discharge in top of the same barrel, and I recirculate that barrel for however long it takes to totally emulsify the entire barrel until it looks like hand lotion. This process might take 15 minutes and up to maybe near an hour, depending on the WVO and temperature.


Once emulsified, I just let it sit for a week or so. I use white barrels so I can see the stratification of the liquid in the barrel. What I end up with is black gunk on bottom, a layer of water, a layer of animal fat like lard, and on the top of all of it is beautiful, clear, clean veggie oil that looks like honey, usually about 40 gallons of fuel.

Filter Into Ready Fuel Supply Barrels

I then pump from the top of the “honey” through two Walmart Pur water filters. First, I use the 20 micron filter and then a 10 micron filter. Then, I run them inline into my “ready fuel supply” barrels for use.

Left Overs

What about the junk left in barrel bottoms? I emulsify the left overs, pump it into my “junk” barrels, and let it accumulate. By the time the barrel is full, you can pump about 15 gals of “questionable” honey into a barrel with fresh WVO and process it again. I pump the water from the bottom of the “junk” barrels. It will have sugar/salt and other soluble cooking ingredients in it. The black stuff in the bottom is from coatings on the stuff deep fried. The white stuff is animal fat. I’m sure if I think about it, I will find a use for the animal fat. My chickens like it.

Fuel System on Diesels

How I set up the fuel system on my diesels is inexpensive and easy. Two separate systems combine to make your diesel WVO usable.

WVO Preheat System Parts

For the WVO preheat system, you will need some heater hose, hose clamps, and a couple T’s, two ball valves (so you can shut the coolant off from the heat exchanger; it’s not necessary but lets you isolate your engine’s cooling system) to set the system up to preheat the WVO in combination with a heat exchanger, Ebay 20-plate Copper Brazed Heat Exchanger 5″x12″ , WVO SVO, Boiler, Wood furnace.

Dual Fuel System Parts

The dual fuel system is also very simple, once you wrap your brain around it. You need a fuel tank for WVO, fuel line, (I use the red air hose from Hodepo for fuel line; it works!), a low pressure 12v auxiliary fuel pump, two two-tank fuel switch valves,(I use manual marine brass valves or the Ford two tank electric valves), and an auxiliary 10 micron fuel filter.


To install these systems, put the WVO fuel tank wherever it fits. At one time I had a 55 gallon barrel in the back seat of my 240D, so I was good for 1500 miles. Install the auxiliary fuel pump in the WVO supply line. Install the heat exchanger in the engine compartment. Install two tank valves, fuel lines, 10 micron filter for heated WVO. Make sure you have switch valves installed so WVO returns to WVO tank and diesel fuel returns to diesel Fuel tank. I know this is a vague set of instructions for installation, but if you don’t “get it” don’t do it; you don’t have enough expertise and you could screw up a valuable diesel engine.

Switching to WVO

I always start on diesel and switch to WVO when the engine water temp is over 100 degree F. When the engine reaches temperature, I switch the fuel return valve from the diesel tank to the WVO tank. Then I switch the fuel supply valve from diesel to WVO. Now you are 100% on WVO.

I leave the system on WVO for running errands, and if the engine will not have enough time to get cold before the next start. You will not notice any difference starting on WVO or diesel, if the engine stays warm. When I shut the engine down for the night or an extended period of time, I first switch the fuel supply valve to diesel and let the engine run a couple of minutes to flush the primary filter, injector pump, and injectors of WVO. This will also run a small amount of return diesel fuel into your WVO tank. (I have more about that later.)


Pay attention to this! If you use purely WVO as a fuel, you must pay tax on it. However, there is no tax required on fuel additives! My WVO tank always has some diesel fuel in it, due to the shutdown flush process. There are no laws that I know of that regulates a limit on the percentage of allowable tax free additives in fuel, so all WVO I burn is an additive to the diesel fuel, even if it is 99% WVO additive. It also burns cleaner and reduces pollution from exhaust.

As an idea to pursue for the adventurous, you can add a jar of water with some electrodes in it that bubbles HHO gas [–a 2:1 mixture of oxyhydrogen–] into the air intake and increase your fuel mileage 15% or so. I’m just saying’. However, ya better know what you are doing, because HHO can make sudden loud, dangerous noises if you mess up.

My Experience and Cost

My WVO experience has been all good. It usually costs me less than $200 to set a diesel up to run on WVO, but I scrounge tanks, switch valves, and fuel filters. It pays to start with a new auxiliary fuel supply pump. Tear down an engine that’s been run on WVO for a while, and it is clean like new inside. The WVO burns clean and get rid of all the stuff diesel fuel leaves in your engine. WVO is stinky and messy to collect and process, but I am messy. It gives me great satisfaction to be able to use WVO, not to mention my costs are about a nickel a gallon, and it really doesn’t smell like french fries running down the road.

SurvivalBlog Writing Contest

This has been another entry for Round 79 of the SurvivalBlog non-fiction writing contest. The nearly $11,000 worth of prizes for this round include:

First Prize:

  1. A $3000 gift certificate towards a Sol-Ark Solar Generator from Veteran owned Portable Solar LLC. The only EMP Hardened Solar Generator System available to the public.
  2. A Gunsite Academy Three Day Course Certificate. This can be used for any one, two, or three day course (a $1,095 value),
  3. A course certificate from onPoint Tactical for the prize winner’s choice of three-day civilian courses, excluding those restricted for military or government teams. Three day onPoint courses normally cost $795,
  4. DRD Tactical is providing a 5.56 NATO QD Billet upper. These have hammer forged, chrome-lined barrels and a hard case, to go with your own AR lower. It will allow any standard AR-type rifle to have a quick change barrel. This can be assembled in less than one minute without the use of any tools. It also provides a compact carry capability in a hard case or in 3-day pack (an $1,100 value),
  5. Two cases of Mountain House freeze-dried assorted entrees in #10 cans, courtesy of Ready Made Resources (a $350 value),
  6. A $250 gift certificate good for any product from Sunflower Ammo,
  7. American Gunsmithing Institute (AGI) is providing a $300 certificate good towards any of their DVD training courses.

Second Prize:

  1. A Model 175 Series Solar Generator provided by Quantum Harvest LLC (a $439 value),
  2. A Glock form factor SIRT laser training pistol and a SIRT AR-15/M4 Laser Training Bolt, courtesy of Next Level Training, which have a combined retail value of $589,
  3. A gift certificate for any two or three-day class from Max Velocity Tactical (a $600 value),
  4. A transferable certificate for a two-day Ultimate Bug Out Course from Florida Firearms Training (a $400 value),
  5. A Three-Day Deluxe Emergency Kit from Emergency Essentials (a $190 value),
  6. A $200 gift certificate good towards any books published by,
  7. RepackBox is providing a $300 gift certificate to their site.

Third Prize:

  1. A Royal Berkey water filter, courtesy of Directive 21 (a $275 value),
  2. A large handmade clothes drying rack, a washboard, and a Homesteading for Beginners DVD, all courtesy of The Homestead Store, with a combined value of $206,
  3. Expanded sets of both washable feminine pads and liners, donated by Naturally Cozy (a $185 retail value),
  4. Two Super Survival Pack seed collections, a $150 value, courtesy of Seed for Security, LLC,
  5. Mayflower Trading is donating a $200 gift certificate for homesteading appliances, and
  6. Two 1,000-foot spools of full mil-spec U.S.-made 750 paracord (in-stock colors only) from (a $240 value).

Round 79 ends on November 30th, so get busy writing and e-mail us your entry. Remember that there is a 1,500-word minimum, and that articles on practical “how to” skills for survival have an advantage in the judging.


  1. What’s the shelf life of WVO?

    What additives do you add for cold weather?

    Great introduction via this post and would like to see more details and the nuts and bolts to make this all work.

  2. Tri Angle farms. In winter the bottom sludge will freeze solid. My friend cuts the 5gal jugs into a screened vat. Frozen junk goes to the pigs. They love it and get as big as Volkswagen’s.

  3. This article has my vote for one of the most useful articles of the year on this blog. Even if someone does not have a diesel-engine vehicle it would be good to bookmark and print this one because, you never know. My copy will be with my War Dept. booklet on wood gasifier conversions for tractors.

  4. I’m a sight oriented guy. Too bad there weren’t a few pictures and diagrams to illustrate this excellent article.
    I don’t have a Diesel, nor do I intend to get one. But a continuing education is never wasted.

  5. I run black diesel (WMO waste motor oil) I like the simplicity of running WMO, the way you process your WVO is also very simplistic. As for the waste animal fat you can always make soap out of it (:(:

  6. Fantastic article… especially the part about processing the oil. Years ago I looked into bio-diesel, but I was put off by the chemical process required (potassium hydroxide, etc.)
    Processing with water is brilliant.

  7. I’ve had injector issues running filtered used vegtable french fry oil in my 2016 toyota hilux truck, due to the unseen sediment, and the type of fuel pump in the ‘common rail’ injector system. The injectors would clog, and are expensive to replace. Using heating oil has the same effect.

    However, on my other diesel motors, like the perkins in my mf-35 tractor, and the older motor in my Mercedes unimog, the french fry oil works fine, but only in the summer. In the winter it is more of a pain in the butt to get flowing than it is worth. I have also tried it with a separate filtering system in my Viesmann house heating system, but the burnt residue collects in the exhaust heat exchanger and shuts down the system. After cleaning all jets and pumps, and converting back to heating oil, the residue caught fire and burnt the modern polycarbonate flue, and about burnt down my house. The two 4,000 liter HDPE oil tanks almost caught fire in my basement.

    So, my comments are that you should use caution when using french fry oil and heating oil in a modern common rail diesel, and never use the french fry oil in a modern home heating furnace. Yes, I live in Europe, and my comments may not apply in the US.

    Some of the ‘residue’ can be used to make soap, but is a lot of work. I use the french fry grease residue to mix with sawdust and burn it in my basement wood stove after i have a good bed of coals. It smokes real bad, but puts out a lot of heat. I have a used motor oil drip system (don’t tell the gummint!) Heater that i can also run on the used french fry oil, but it burns too good, and sometimes the flame backs up the supply line, and that always creates a real exciting situation. My general observation is that it is good to know how to do it, and keep that info handy for the future, but used french fry oil is a somewhat pain in the butt work, and the benefits outweigh the mess, inconvenience and smell. I seem to smell like french fries for days after i monkey with it.

    Good article though, thanks.

  8. As mentioned in the case of the Hilux above, WGO doesn’t do well in modern, high pressure, diesel fuel systems. Basically, if the diesel engine requires (has) a computer to run it, WGO should be avoided. If you do use WGO in these modern fuel systems, you’ll be replacing injectors, pumps, and the fuel lines between the pump and injectors.

  9. I’ve been meaning to read up on this for a while now. My family used to do this in the early 2000’s with two old Mercedes station wagons. I remember that we had a large straining operation going in our backyard, but couldn’t really remember the process. Thanks for the article.

  10. I know a diesel mechanic who had a 1999 Ford 7.3L van towed into his shop. Engine wouldn’t run. Fuel system was fouled very badly with veggie oil, and after about $4,000 in repairs, the van (owned by a rock band) was ready to leave. With diesel fuel in the tank. When asked how long their work was warranted for, the mechanic said, “Our warrantee expires when I see your tail lights, because I know you’re going to put that veggie oil crap back into that perfectly good engine.”
    I think WVO may work on older engines, but as Even Martin noted, anything of recent vintage with a computer, it’s not going to end well.
    I know that some batches of real diesel fuel have ruined a lot of engines because it was out of specification. Just wondering, what is the cetane rating on WVO? Or, WMO?
    My 7.3L has run just fine for 440,000 miles on real diesel. I won’t be using WVO in my engine, but you never know… was an interesting article. In 2015 I ran 14 year-old fuel through it for a year without a hiccup. Could get a speeding ticket in any jurisdiction in North America. i store about 2500 gallons of diesel for rainy days. [When diesel hit $1.45/gallon I filled up the large storage tank!] Think I’d trust older fuel over WVO if I had it.
    Thanks to the author for noting all the engines he used it in. All were older engines…and he’s obviously good at keeping these on the road.
    i got a batch of bio-diesel in New Mexico once, and it sure cleaned up my tank! All the crud that was living in there clogged up my fuel socks (in the tank), fouled some other fuel system components, and sent me to a shop in Amarillo for a day. That fill-up cost me $2200.00. Not a fan of bio.

  11. Just a note to those who may have tried WVO/WMO and had trouble with fouling.
    As the author has noted, it is best to run two tanks, one with pure diesel the other for your wvo/wmo….it is imperative to filter well, warm your incoming waste oil and start and stop the engine on pure diesel. Do you due diligence it is WORTH the trouble!

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