• Apr 4th 2006 at 12:13PM
  • 99
One lesser-known movement in green car technology is converting diesels to run on SVO, or Straight Vegetable Oil. Unlike biodiesel, which is produced by chemically modifying vegetable oil so that it can be used in a diesel vehicle with no modifications, SVO requires a second fuel system for the vegetable oil in addition to the standard diesel fuel system. Also, one doesn’t operate and fill up an SVO vehicle like a normal petrol or diesel car. It sounds like a lot of work, so why are more and more people kicking up the veggie quotient of their diesels’ diet? We decided to look into it.

No automaker offers an SVO-powered vehicle in its line-up, so tapping a press fleet for a quick evaluation was out of the question. Fortunately we stumbled upon Chuck and Tom Norton, a pair of sibs who run Turtle Plastics, an eco-friendly plastics business in Lorain, OH.  The Norton boys recently had a 2003 Volkswagen Jetta TDi converted to run on SVO. Though Tom’s the primary driver, Chuck was happy to hand over the keys to their “Vega Jet” for a spin last week and helped us understand what it’s like to own and operate a vehicle that eats out of a dumpster. Let us explain…

Vegetable oil can be found in abundance throughout our daily lives. It’s the can of canola or pint of peanut oil in the back of your kitchen cabinet. It’s also the vat of boiling grease in which fries are drowned at your local family restaurant. People who own SVO vehicles often get their fuel for free from restaurants, literally taking it right from the grease dumpster out back. This gives SVOs their reputation as dumpster divers, but it also means an SVO vehicle can potentially pay for its $2,000-$3,000 conversion in less than a year thanks to free fuel. Owners shouldn’t count on free grease as a given, but America’s appetite for fried foods knows no bounds so the supply seems virtually limitless.

Before we dive deeper into the question of why someone would choose to convert a vehicle to run on SVO, let’s go over exactly how it works. While modern diesel engines require no modification to burn vegetable oil, a separate fuel system is required because SVO takes on the viscosity of a cinder block as the temperature drops. On account of this, a diesel fuel system is still needed to operate the vehicle until the SVO can warm up and thin out.

Though each installation is different, an average SVO conversion involves adding a separate fuel tank, filter and fuel lines for the vegetable oil, as well as modifying the coolant system to transfer the engine’s heat to these new components. On the Nortons’ Jetta the fuel lines carrying SVO up to the engine are cleverly packed with coolant lines that run all the way to the SVO fuel tanks custom mounted in the trunk.

At startup the “Vega Jet” will run off of its diesel fuel system until the engine has warmed. Normally that heat energy would be lost via the car’s radiator, but this SVO vehicle reuses the heat thanks to the modified coolant system that quickly thins out the vegetable oil so it can flow freely in the system.

After about five minutes of operating on diesel the fuel systems can be switched and SVO can take over combustion duty. The two fuel systems meet up front under the hood where a solenoid is activated via a dash-mounted switch to change between the two. From there the two fuel systems share a fuel line for a short distance, usually about eight inches. The Nortons need to purge that line of vegetable oil if they’re going to leave the car to cool down after being used. This involves simply switching back to diesel fuel for the last five minutes of a trip. If vegetable oil were left in the fuel line to cool and congeal, it would block the flow of diesel on the next start up.

Full Circle Fuels in Oberlin, OH converted the Norton brothers’ “Vega Jet” to run on SVO by installing a pair of custom fuel tanks in the Jetta’s trunk. The Nortons must open the trunk in order to fill the smaller tank, which then automatically feeds a larger one fitted under the floor and around the spare tire. The system hardly reduces the useable trunk space, except for the SVO paraphernalia stowed back there to facilitate transporting barrels of veggie oil filled up at local restaurants.

Situated near the bay doors of the Turtle Plastics warehouse is a large storage tank for vegetable oil. The fuel is transferred through a tube to the car’s fuel tank via gravity since the storage unit is elevated above the dock in which the Jetta is parked. Before used grease from a restaurant is added to the storage unit, however, the Nortons must filter out any impurities using a filter bag. SVO vehicles can also run on fresh, unused vegetable oil, and Full Circle Fuels helped the Nortons score this pallet of expired cooking oil for around a $1.50/gallon. Remember when gasoline was $1.50/gallon?

We had a chance to drive the “Vega Jetta” on local roads and are happy to report that the experience was pleasantly ordinary. While the “Vega Jet” handles like there’s a hippy locked in the trunk due to the extra weight of the SVO tanks, acceleration and overall performance was on par with other diesel-powered Jettas we’ve driven. The only interior modifications we could find were the purge switch located on the Jetta’s dash and a fuel gauge custom-mounted in the door to keep tabs on the SVO tanks.

Although not much study has been performed on the emissions of an SVO-powered vehicle, they are comparable to what a biodiesel powerplant puts out, which is a marked improvement over that of a straight diesel. According to the website Energy Bulletin, there are no sulfur emissions, lower unburnt hydrocarbons, and somewhat lower carbon monoxide and particulates. While biodiesel has been shown to emit slightly higher levels of nitrous oxide than diesel, studies performed locally by Full Circle Fuels itself have indicated that running on straight grease emits less NOx than even diesel. SVO vehicles are virtually carbon dioxide free, as well, except for the small amount of CO2 released during start up or purging while running on diesel. Assuming one is careful about purging the vegetable oil from the vehicle’s fuel system, an SVO-powered vehicle will also enjoy the same durability as its diesel-powered countered thanks to the natural lubricity of vegetable oil.

Fuel economy also remains largely unchanged from a similar diesel-powered vehicle, which is to say these things will go great distances on a tank of grease. While saving money on fuel was an attractive quality for the Norton brothers, their reasons for burning vegetable oil are more closely aligned with the desire to use renewable resources that leave less of an impact on the environment than gasoline or diesel fuel, as well as the oft-cited hope that one day this country won’t be beholden to other oil-producing countries for its energy.

While this review was meant as a window into a day in the life of an SVO-equipped vehicle owner, we plan to return to the topic of SVO again in the near future to examine how the greasy technology fits into the increasingly varied mix of alternative fuels and powerplants. We’ll introduce you to Sam Merret and Bob Beckett, the two SVO-advocates that operate Full Circle Fuels in Oberlin, OH and perform SVO conversions on a daily basis. We’ll also examine Golden Fuel Systems, of which Full Circle Fuels is an affiliate of sorts. Formerly known as Greasel, Golden Fuel Systems is widely considered one of the best producers of SVO conversion kits in the business. Until then, we hope you’ll look twice at the bottle of cooking oil in your kitchen cabinet knowing that there’s a “Vega Jet” driving around looking for some free fuel to sip.

Related Links:
Turtle Plastics
Energy Bulletin
Full Circle Fuels
Golden Fuel Systems/Greasel

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    • 1 Second Ago
      Liz Wegner
      • 9 Years Ago
      Sounds like a good idea, unfortunately, the big oil companies will more than likely fight it, and try no to let it happen. If I had an extra $2,000, I`d convert my Chrysler PT Cuiser to be able to use Vegitable oil! it would save me over $100.00/month!
      • 9 Years Ago
      • 9 Years Ago
      Sorry, I didn't close my argument. By driving these cars, don't be fooled, you are still releasing CO2, you are still giving kids asthma, you are still the problem. In the short term it's better to keep this oil as waste, ship it to a landfill and let it release its carbon slowly away from urban streets and places where people have to actually breath. Does that mean you turn back to using fossil fuel? No, just stop driving and you'll keep your hippy creds intact. If you can't do this, then please shut up and stop telling everyone that you've found the answer.
      • 9 Years Ago
      There are many bands touring on the stuff check out these guys touring on a converted coach: Hot Buttered Rum www.hotbutteredrum.net

      They have song called Well-Oiled Machine that sums it all up
      • 9 Years Ago
      It's good that all of you bashers are looking at this from all angles and not just accepting the "new and all-powerful cure." However, why not accept the fact that at least someone is making an honest and concerted effort to cut loose the proverbial ball and chain from the middle eastern countries.
      • 9 Years Ago

      The difference is the CO2 that's being emitted was perviously removed from the atmosphere by the canola/soybeans/what-have-you. It thus becomes "carbon neutral".
      • 9 Years Ago
      Some quick answers/points:

      84. That's disgusting, have you ever smelled or handled used grease? Pretty foul, yes, but not as bad and not nearly as toxic as gasoline.

      88. I WANT TO HAUL HORSES. BESIDES JUST STRAIGHT ROAD TRAVEL, HAS THERE BEEN STUDIES ON A HEAVIER DUTY VECHICLE FOR BAD ROAD CONDITIONS AND WEIGHT THAT WOULD BE PRACTICAL AND SAFE? Umm, a diesel truck from any of the big 3? Biodiesel would probably be more convenient (no mods necessary), just make sure it's ASTM certified.

      94. can it be done to a normal gas engine No, you need a diesel.

      104. Re: carbon neutral. See comments concerning timescale about 4 pages back (hint: where did the carbon in the SVO come from and when did it get there?)
      • 9 Years Ago
      Hey Jaymez, if your commute is less than 10 minutes by car, then why don't you ride a bicycle? It's the ultimate zero-emissions vehicle!!

      If you must drive, then WVO or biodiesel seems the best way to go in today's market. If we support the technology now, it will only get better.
      Grease Mom
      • 9 Years Ago
      2 things
      1 Of course burning VO releases CO2 into the atmosphere.

      2 my greasecar system flushes in 45 seconds. I don't know why the greasel system takes so long to purge. I do not always switch over for short trips anyway, But I have a 45 minute commute.
      Mark Krull
      • 9 Years Ago
      Am wondering if diesel hybrid technology (which, if one can believe what's been written, has been used to produce prototype cars achieving very superior fuel economy-ie: 118 MPG by VW) can be integrated with SVO
      and/or related vegetable based fuels.
      • 9 Years Ago
      I'm gunna need more explanation of this. As far as I know, vegetable oil is a hydrocarbon. Burning hydrobarbons produces CO2 and H2O plus impurities. How are these things "virtually carbon dioxid free"?

      Plant hydrocarbon is made out of CO2 and H2O (look at the green stuff outside to see what I mean), so in burning it you are closing the cycle. A better way to put it would be "virtually carbon neutral". Of course, this is true for petroleum -- the difference is timescale. SVO (and WVO -- which is what this article really describes, not SVO -- and biodiesel) are carbon neutral on a time frame of a year or so; petroleum is carbon neutral on a time frame of ~100 million years.
      • 9 Years Ago
      I think this is a stupid "addition" to a jetta. Let's be realistic about our money. Okay, let's analyze. A 2003 Jetta GL Turbodiesel gets 45 Highway MPG. So in it's 14.5 gallon tank, you are getting MAX 652.5 MPT. Okay, let's say that this new veggie oil deal is $2500 after installation which is a very low, unrealistic price. In the jetta, you will have to fill up your car 62.5 times at the price of 2.75 a gallon. That is 40, 781 miles before you even get your money back! On top of all of that, if you don't own a diesel jetta, which the majority of americans don't if your over the age of 21, wouldn't it be more expensive to trade in your vechile and buy the car in the first place than it actually is to just pay for your gas?
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