Here is a sincere warning that goes out to anyone considering converting a car to run on waste vegetable oil (WVO) as I did: you are about to become a rock star. After only one visit, restaurants will know you by name, auto shops will call their friends to show you off, and people in the parking lot will want pictures with you with greasy hands. Thanks to recent television coverage, WVO is a fashionable topic in American living rooms, and when you arrive at the deli requesting dirty oil, they will act like you are their long-lost cousin and do everything but pinch your cheeks.
The Birth of Diesel
The first diesel engine, dubbed the “Black Mistress,” was invented in 1893 by Rudolf Diesel. Obviously, there wasn’t diesel fuel before there was a diesel engine, so in the years that followed, Diesel perfected his invention and discovered that this engine could run on practically any hydrocarbon, including shale oil, refinery tailings, coal dust and—get this—peanut oil.
I feel like I’m just taking my little Black Mistress back to her roots. Letting her natural knotty hair grow out. Feeding her the food she was meant to eat, you know? Running vegetable oil is what this engine was designed to do!
Biodiesel Versus WVO
I run waste vegetable oil, which is different than biodiesel. Biodiesel is a vegetable-oil or animal-fat-based fuel that can be run in any diesel engine without modification (yes, right now in any diesel engine). The benefits of biodiesel are that it reduces emissions by 80% compared to gasoline and can be purchased at the pump in many large and small cities. (It is especially common in middle America, where farmers have been running biodiesel for decades.) However, it is a highly refined fuel—often processed from virgin oils or fats—that utilizes highly toxic chemicals such as methanol (not to mention electricity) in its production, and costs anywhere between $2.30 to $3.80 per gallon.
WVO is literally just used kitchen grease. The processing of it involves nothing more than hand-filtering to remove the deep-fryer floaters (water and microscopic food particulate). Like biodiesel, WVO reduces emissions by 80%. But WVO has these added advantages:
The drawbacks of WVO are (if you consider them drawbacks): you won’t be hanging out at gas stations anymore and, indeed, a little Do-It-Yourself effort will earn you the right to offer under-the-hood public interviews.
Now, although the Black Mistress of 1893 could handle the most gelatinous of greases, modern diesel fuel-injection systems have been engineered to run on low-viscosity diesel fuel. They can handle thick grease only if the viscosity is reduced first. This can be accomplished in one of two ways: chemically (transforming the oil into biodiesel) or thermally. By heating the oil to 160-180 degrees, the viscosity is reduced to that of diesel fuel and voila! Rudolph’s dream is realized.
So the conversion process is not an engine conversion at all, but add-on hardware that heats and filters the WVO before it gets to the engine. On my car, a hot little 2001 TDI VW Jetta, the add-ons begin at the main tank, which holds 15 gallons and is now used for waste vegetable oil. Two electric heating pads (drawing seven amps each) are installed underneath the main tank. They start heating the grease as soon as your key turns in the ignition.
From the heated main tank, a new fuel line is run to a custom 10-micron veggie fuel filter in the engine. The new fuel line is “wrapped” in two lines of coolant borrowed from the radiator, assuring that when the engine reaches running temperature, the already heated main-tank veggie fuel will maintain its 190-degree temperature all the way to the fuel filter, which is wrapped in another seven-amp heating pad. At this point, the veggie fuel—filtered and fluid—is ready to go!
My personal conversion includes one additional add-on to accommodate the compulsive gypsy lifestyle I lead. You see, I can’t tell you where I will be next week, let alone next winter, so I chose to install a two-tank system on my car. The two-tank system equips my WVO machine with a small five-gallon auxiliary tank (mine sits in the trunk around the spare tire) that is filled with biodiesel or diesel for cold-weather start-up and shutdown. When temperatures fall below 50 degrees, my Jetta prefers a two-block biodiesel transition. Mercedes, BMWs, trucks, semis and tractors will obviously have preferences of their own. It is fair to say that every installation is a custom conversion.
Prefabricated conversion kits start at $600 and go up to $3,000. Fortunately for those with the ambition, mechanical inclination and a good set of socket wrenches, converting a diesel engine to run WVO can be an inexpensive and very rewarding do-it-yourself endeavor. My personal conversion kit and installation cost a total of $2,500, which included four extra $40 veggie fuel filters, a $30 stash of filter bags and a $160 electric pump, all of which I would highly recommend. The electric pump plugs into my lighter outlet and is used to pump grease from one container to another, or from one container to my tank. The pump is lightweight and portable so this mini-skirt-wearing WVO chick can lift it without injuring her back—so nothing interferes with her autograph signing.
Indeed, fueling your car with WVO requires more commitment and consciousness than pulling up to the gas pump. But if I wanted average results, I’d be doing what average people do. I’ll settle for nothing short of extraordinary this time ’round and if it takes a little extra effort to make sure the neighbors’ kids have clean drinking water or my grandfather enjoys deep breaths of fresh air, it’s no hassle at all. In fact, it just might be precisely what I’m here to do.