Straight Vegetable Oil SVO as Diesel replacement fuel
FAQ - Frequently Asked Questions
Is this a new idea?
No. Diesel's first engines ran on peanut oil. Soon after, fossil oil (mineral oil) became widely available and inexpensive, and became the dominant fuel in the world. Engine and fuel system development for the diesel therefore became centered around "diesel fuel" - a less viscous fuel than vegetable oil. This is why we now have to use either the "heating" approach or the "biodiesel" approach to make vegetable oil thin enough to use in existing diesel injection systems. We are adapting the fuel, rather than the engine or the existing fuel system. The original fuel system remains intact, and the engine can use diesel fuel at any time. Despite the fact that vegetable oil was used in early diesels, its reappearance of vegetable oil on the world fuels scene is relatively recent, so from that standpoint, it is a relatively unknown and underutilized fuel. This is changing quickly - there are now literally thousands of engines using SVO and WVO.
User experiences have been generally positive, but because SVO does not have the extensive testing of diesel fuel or even of biodiesel, any SVO system should be considered to be "experimental". Internet-based databases of real-world experience with SVO use have been established. These will help further the acceptance of SVO. One of these is based in Germany. Please see our links and article page for the hyperlink.
Will it work for my gasoline (petrol) car?
No. This is only for diesel engines. Diesels work by compressing air much more than is the case with a gasoline (petrol) engine. This creates high temperatures, and causes a fine mist of injected oil to self-ignite from the heat of compression and combust. The fine mist ("atomized") oils injected into the cylinder just before the piston reaches the top of the compression stroke. There is no spark plug or ignition system in a diesel engine. It is designed to burn a light viscosity oil. Vegetable oils are heavier/thick/more viscous, and so need to be made thinner (less "viscous", lower "viscosity") to work. This is why "biodiesel" (alkyl ester, usually methyl ester) is made ....or, alternatively, why vegetable oil is preheated in our systems.
The chemical process of making biodiesel, or the pre-heating of the vegetable oil both achieve this goal: reduction of viscosity. If that is done, then the engine will run. But never a gasoline engine, only diesels!
Why aren't there more diesels running on vegetable oil?
Until recently, diesel fuel has been relatively inexpensive, and its negative environmental effects were not well understood. As diesel fuel has become more scarce and expensive and the negative environmental and political consequences of reliance on nonrenewable fossil fuels has become obvious, interest in vegetable oil fuels has increased exponentially.
STRAIGHT VEGETABLE OIL
What's the difference between straight vegetable oil ("SVO") and "biodiesel"?
SVO is just that - nothing but pure vegetable oil.
The term "biodiesel" usually refers to alkyl ester (usually methyl ester). These esters are derived from vegetable oil. The sticky glycerine (glycerol) component of the original triglyceride (vegetable oil) is replaced with another alcohol component via the process known as transesterification. Methanol is most often used for this, since it is widely available, the least expensive, and gives a reliable chemical reaction. (Methanol is sometimes called "wood alcohol", even though it has not been made commercially from renewable sources like wood for many years, but rather from non-renewable natural gas).
Even low levels of exposure to methanol, over longer periods of time can be a problem:
"Clinically, chronic, low-level exposure to methanol has been seen to cause headaches, dizziness, nausea, ear buzzing, GI disturbances, weakness, vertigo, chills, memory lapses, numbness & shooting pains, behavioral disturbances, neuritis, misty vision, vision tunneling, blurring of vision, conjunctivitis, insomnia, vision loss, depression, heart problems (including disease of the heart muscle), and pancreatic inflammation" (Kavet 1990, Monte 1984, Posner 1975).
Ethanol (grain alcohol) is renewable, and safer, in terms of accidental or occupational exposure, and can be used, but is more difficult and expensive to work with - really to the point that most small-scale and commercial producers of biodiesel do not use ethanol, even though they would like to.
Biodiesel making requires these chemicals, their mixture, to make a catalyst, safe heat sources, a mixer/processor of some sort, and finding some way to use the glycerol (approx. 15% glycerol is obtained from each batch). Often, biodiesel "home brewers" (including us, in the past!) find that they really don't have a use for the glycerol, and it accumulates and needs to be composted or disposed of.
Storage, handling (spill/splash), heating (flammability and explosion), respiration, and ventilation concerns must be taken seriously when making biodiesel. Also, in some regions, it is difficult and/or expensive to obtain the needed materials.
Closed biodiesel processors, explosion-proof motors, etc. are highly recommended!!
While many people do enjoy making biodiesel, and do so safely, making a quality product, others prefer the SVO approach for its ease of use and freedom from reliance on chemicals. For those who travel and collect oil along the way, SVO is much easier than making biodiesel "on the road".
SVO use, by contrast to biodiesel, requires a heated fuel system, and most often a second fuel tank and filter, to be able to start the engine, move the SVO from tank, through fuel lines, filter, injection pump and injectors, as well as to accomplish the best atomization within the engine (lowest emissions, and least likely to cause harm to the engine).
The objective is to heat the vegetable oil to approx. 70C (158F) at the point of injection. Note that it is not necessary, or even desirable, to try and heat the SVO to this high temperature in the entire fuel system, only at the point of injection! So, SVO can be heated "progressively", along it's path from the tank to engine, and it is most effective to use a combination of coolant-based heaters at the tank, at the filter, etc. and then use an electric heater just before the injection pump. In many cases, in warm and moderate climates, good new or lightly used cooking oils, it is not necessary to use a tank heater. However, with thicker "grease", that is, vegetable oil that has become more "hydrogenated" by its time in a fryer at high temperatures, and this in combination with cooler ambient (outdoor) temperatures, tank heaters can certainly be desirable. As an example, a system could function perfectly in Arizona or California, or other warm/hot climates, year round, even on used cooking oil, without a tank heater and without a "heated path" (heating of the SVO fuel line by running coolant lines from the engine along its path to the tank)
Will "SVO" work for me? What engines have your kits been used on?
SVO is preferred by many people for ease of use. It will work well for many diesel owners. Our kits or components (e.g. Vormax, Vegtherm, 6-port motorized fuel selector valve) have been used on the following applications, to our knowledge (there may be others we are not aware of, of course)
Dodge Cummins, mostly 12 valve models, perhaps a few 24 valve models.
Ford IDI (6.9 and 7.3L, both turbo and non-turbo) and Powerstroke (with optional Powerstroke Package, contact us for details)
GM 6.2 and 6.5, turbo and non-turbo
Mercedes 240, 300, turbo and non-turbo, and pre-86, as well as newer models
VW 1.6 and 1.9, and 1.9 TDI
Ford and John Deere tractors
What fuels can I use after I have added an SVO kit to my car?
Diesel, biodiesel, new or used vegetable oil.
*NOTE*: Can you still run diesel, can you blend, and can you run diesel in the SVO tank?
Yes, yes, and yes! If you go single tank you can also mix fuels or run diesel anytime in any proportion.
How well does it work in cold weather? What do I need for where I live / for my vehicle / for the oil I will be using?
Depending on the oil you use and the vehicle condition, our systems can be specified and equipped for cold weather use. Options such as Hotfox tank heaters, Hotplate heat exchangers, the Vegtherm, 120V pad heaters applied with an adhesive to the outside of the SVO tank, etc. are all available from us. 120V engine block heaters, oil pan pad heaters, propane or diesel-fired "parking heaters" for pre-heating the engine are a very good idea, since they will reduce the time to "switch-over", and minimize the required "purge" times when using "two-tank" systems, and will extend the lower ambient temperature limits of "single tank" systems (see below, and other sections of our site, for more details on the two-tank and single-tank systems, and their application). Here are some example applications, and what we would recommend:
SCENARIO #1: Warm Climate
"I live in California, where it hardly ever goes to freezing in winter, I have an older Mercedes, and I intend to use oil that will not go solid in the tank even in the colder months of the year. The engine compression, starter, glow plugs, battery, and connections are all good"
RECOMMENDATION: Ideal candidate for a single tank system, with no other options.
SCENARIO #2: Moderate Cold
"I live where it gets to around freezing, but not much below, in winter. I intend to use fairly good oil, but I am not sure it will always be liquid in the tank"
RECOMMENDATION: A two-tank system is needed here, with a tank heater (Hotfox or pad heater...the Hotfox or other coolant-based tank heater (solid plate welded in side or bottom of aluminum tank, for example, NOT a "transmission cooler" or "copper loop"!) Modified transmission oil coolers have been known to leak, and cause coolant loss. Copper coils in tanks may also crack, in time, from vibration, and vegetable oil reacts with copper to form a "greenish slime" - not something you want happening in the tank! The Hotfox is rugged, welded stainless steel. A solidly engineered component that effectively heats the oil in the tank both outside itself and as the fuel is picked up and travels through the fluted fuel pickup tube on its way up the Hotfox and to the engine.
SCENARIO #3: VERY COLD CLIMATE
I live where it gets really cold in winter. The "oil" will be a solid mass every morning for months in the winter, even if I were to use new oil, or very good used oil, it would be semi-solid or solid.
RECOMMENDATION: A two-tank system and a Hotfox tank heater needed, and perhaps additional heating options, such as Hotplate, pad heater on the oil pan (120V) if not already equipped with a block heater.
What if I forget to "Switch back to diesel"?
If you forget to purge the vegoil out, and shut the engine off for more than an hour or so, you may have difficulty restarting, even when you've switched back to diesel. We include a buzzer with our kits which will sound if the ignition is shut off, but the fuel switching valve is left in the "SVO" position. Then engine is then restarted, switched to the "start/purge" fuel, run for a minute or two, and shut down.
How do your Vegtherm Standard and Vegtherm MEGA heaters work?
The Vegtherm is a 12 volt inline heater. It was designed specifically to heat vegetable oil to a maximum of ~ 70 C. (assuming an inlet temperature of min. 25 C...room temperature and matching the heater(s) to the task, namely the flow rate of fuel to be heated in a specific application).
Power is supplied via a relay. In "two-tank" SVO systems, it is wired so that power is supplied to the heater when the fuel selector is switched to SVO. The oil passes through a tubular section of aluminum that has been designed for efficient heat transfer, within which the inherently self-limiting heating elements are placed. Heat is transferred to the aluminum extrusion and to the vegoil. The design of the heater is proven technology which does not require the use of a thermostat. Amperage draw varies according to inlet temperature and flow rate, rather than continuous on/off cycling. See the Vegtherm product page for more information.
For example, a Vegtherm Mega can draw up to 32 amps @ 12 volts. Typically the heater draws 6-10 amps when first switched on. This quickly rises to a max. of ~ 28 amps, if needed, and then tapers off again to a more steady 10-20 amp range as the "return" fuel begins to recirculate in the system. A Vegtherm Standard draws about 20A at full power. Waste engine heat is added to this return fuel, since the fuel has passed through the injection pump and injectors, and these are heated by lubricating oil (in inline injection pumps) and by the heat of combustion within the cylinder being transferred to the fuel via the hot injectors. If additional heating beyond the capacity of the Vegtherm and the flow rates it was designed for (typical 4 cylinder diesel at cruising speed, with a "looped return") is needed, a Hotplate can be added.
The Hotplate heat exchanger is a high quality stainless steel plate type heat exchanger and is coolant operated (connect to heater lines in engine bay).
Both Vegtherm Standard and Vegtherm Mega units now come with 40 amp auto-resetting circuit breakers, and Bosch relays.
Wiring, connectors, instructions, and rear window sticker are included.
How do your component packages work, and what is included?
Designed to provide an effective packaged solution to using SVO as fuel for a diesel engine.
Details of what is included in various kits we offer can be found at other pages of this site.
I've read that some diesels and some injection pumps don't work well on SVO or WVO - is this true?
Lucas/CAV pumps are reportedly the most likely to fail on SVO. It seems they are subject to high wear rates and have some components that cannot withstand the higher viscosity of SVO (even heated, SVO is thicker than diesel fuel). However, many people use a cautious approach of very fine filtration and thorough heating, and have not experienced failures. The Lucas/CAV would almost certainly not survive long with a single tank system, where the engine is started on SVO. By contrast, the Bosch inline pump as found on older Mercedes engines seems to be especially tolerant of SVO.
Any rotary pump that has been exposed to years of low sulphur diesel fuel, and many hours/miles, may be weak. Many of these pumps fail every year in normal (diesel fuel) use, in any case. Therefore many pumps are rebuilt and exchanged, and so are relatively inexpensive. What seems to happen is that IF (and it does not happen in most cases) a pump fails, and is replaced with a fresh rebuilt pump and the SVO is thinned enough so as not to be too thick, then these pumps work fine for a long time thereafter. In many cases, even older pumps that have never been replaced or rebuilt are working without problems.
Bosch and Bosch-derivative "VE" ( as found in many Japanese diesels) are quite good on SVO.
The Bosch inline (injector lines emerge all in a row) pumps, as found on older Mercedes, mid-90's Cummins, and Land Cruisers, etc. are VERY rugged and highly recommended.
Although the principles of the "two-tank heating approach" with diesel or biodiesel start/stop have been used by many people with good success, the general practice should still be considered experimental. Single tank applications and applications on direct-injection engines are in a higher risk category than older indirect injection and two-tank applications.
What is meant by a "hose-in-a-hose" (HIH) - does your system use this idea?
No, we do not use a "hose-in-a-hose" in the sense of sending coolant down one hose, and running the SVO line inside of that. We consider this too risky. There is the risk that over time, a plastic line or copper or aluminum line could crack (especially if it's kinked, straightened and re-bent, during installation, which happens all too easily!) This could result in engine coolant being slowly lost to the fuel stream, resulting in an overheated engine. Our kit does use a coolant loop from engine, to heated filter (Vormax) and then along the path of the SVO lines and to the Hotfox coolant-operated tank heater, if present.
Can I use waste vegetable oil ("WVO") from restaurant fryers? (used cooking oil)
Yes, WVO can be used in our system. We consider Canola (one variety of rapeseed, and commonly used as a cooking oil) to be one of the best, and certainly there has been more research on this oil for SVO use than others, since it is grown in Germany, where there is more SVO activity than anywhere else. The principle is that the oil to be used needs to be liquid enough to pour, at the ambient temperature you intend to use it. The oil can be "as thick as thick gravy, without needing a tank heater". An oil that is lower on the scale of Iodine Values is certainly best. If the oil is higher iodine value, and higher FFA (such as used soybean oil) it is advisable to keep looking for a source of good Canola oil, or buy new Canola (rapeseed oil is essentially the same for fuel use) oil and blend 50/50. It is necessary to have an oil that will resist oxidation and polymerization. Oil should be collected and used as soon as possible after use in a fryer, and it should be kept sealed to minimize exposure to air, rainwater, and light. We don't advocate "dumpster diving" - there are better ways to get oil and to reduce the risk of using oil that is so poor in quality you may damage injection system or engine parts. Please read the "Used Cooking Oil Fuel" article.
Why do you need to use a "two-tank" system? Don't some people modify their engines to run just on vegetable oil?
We do offer some single tank systems, but at this time only for certain Mercedes. The Vormax filter, mounting bracket, some fittings, the Vegtherm heater, larger diameter fuel lines connectors, wiring, and instructions are included. Only recommended for those operating in warm climates with good, liquid oil. Tank heaters (pad heaters in 120V or 12V, or coolant-operated, the Hotfox) are offered as accessories to extend the capability of this system. We now offer an adaptor which allows the Hotfox to be mounted into the original fuel tank on the older Mercedes sedans.
Special glow plugs, glow plug timers, and "modified injectors" are not needed for these cars, in our experience, if the oil is of good quality, it is a warm climate, and the engine compression, starter, battery, cables, glow plugs, alternator, etc. are in good condition.
What oil is best, for use as SVO?
Canola oil (rapeseed oil, and the related mustard oil) is one of the best and can be located with varying degrees of effort in most areas of Canada and the US, as used cooking oil. Other oils may be less suitable. Basically, a low iodine value oil that resists oxidation/polymerization, and that also had lower free fatty acid (FFA) values, is best. Be aware that some oils have higher Iodine Values (IV is a test method, there is no Iodine in the oil itself) than others, as new oils, and also be aware that FFA values increase as oil is used in a fryer.
I have a Mercedes Benz with the Bosch inline injection pump and pre-chambers - do I still need to use a "two-tank" system and heat the vegoil?
Most of the people running SVO without any heating, in older Mercedes Benz engines, are running new rapeseed oil. They have had quite high success rates. However, other oils, including WVO are MUCH thicker at the same ambient temperature. As mentioned above, we do offer SingleTank systems for the older Mercedes models only, and if the oil is not too thick nor the climate too cold, they work well.
I have a VW - do they work? Do they need an extra fuel pump, since there is no "lift pump"? What if I need to prime the system?
The indirect injection VW engines are fine for SVO. If the oil is liquid and the injection pump in good shape, the oil will flow and work well with our system. Some older, worn pumps may need an electric booster pump, (or a rebuild - it's amazing what a new set of injectors and a rebuilt pump can do!!) but most work well without it. A two-tank (TTVTS) package is recommended.
Ford/GM/Dodge: Many of these have also been converted.
Toyota, Nissan, Mazda: These can be converted. The older Toyota Landcruisers use pre-chamber engines and Bosch-type inline pumps similar to the older Mercedes. In a warm climate, the same setup used on the older Mercedes can be used on a "Canadian" diesel Landcruiser. There are also quite a number of late 80's and early 90's "Japanese right hand drive" diesels entering Canada via importers at this time. A number of our customers have converted these with success and have been operating on used Canola, especially, for some time (over a year, as of June/05). Some have accumulated significant mileages, and have operated in very cold climates with few difficulties, with properly equipped two-tank systems and the right techniques.
What about direct injection, including VW TDI engines? I have heard they're not as well suited as indirect injection (pre-chamber) engines?
Direct injection engines of the older type, as found on tractors, for example, have not been considered to be very well suited for SVO conversion. Newer "TDI" (turbo direct injection), etc. engines are seem to be more suitable than their predecessors. This may be due to the higher injection pressures, injector types, and different combustion chamber and piston designs.
Comments on Journey to Forever (journeytoforever.org), quoting Ed Beggs, founder and president of Neoteric Biofuels Inc. (owners of the plantdrive.com site), regarding the "TDI Controversy" are several years old. These engines have been successfully converted. They seem to be doing as well or better than the earlier VW's.
Where do I get oil?
For SVO (new oil), cold pressed oils direct from farmers or farmer-owned cooperatives would be ideal. The farmers would have a value added product, they could use the fuel themselves, and the presscake pellets form the cold pressing operations can be used as feed, natural fertilizer, and natural pesticide (varies with oil). New crops with rotation or other benefits to the soil can be introduced, and find a market, inedible seeds can sometimes be used, and in some countries, seeds can be harvested from trees/shrubs grown as living fences that provide sticks, fencing, wind erosion and other agro-forestry benefits.(E.g. Honge oil in India). The opportunity to use low value seeds (e.g. "green" or "heated" Canola seed) and add value is created for the farmer, who would otherwise sell these seeds at very low prices.
Oil can be purchased in bulk from oilseed processing plants.
Pubs, chip trucks, restaurants...also from oil pressing plants, fried food factories, etc. Sometimes, new oils are available as out of date food grade oils from food distributors.
If you use WVO from a local restaurant, ask them to put the oil back into the original containers once it is cool, and pick it up regularly to a schedule that works for them.
Again, Canola oil is best. Try to use oil that is as close to "new" in its condition as you can.
Canada is moving to ban trans fats, and more high Oleic Canola is being introduced. As more high-Oleic varieties are introduced (Canola, soy, sunflower), this will find its way to market and to fryers - this is good news for SVO/WVO users!
How do I filter WVO before it goes into the tank?
With our systems, you no longer need to do anything beyond allowing the oil to settle in a warm (room temperature) drum for a few weeks, before use, then pump it thru the Wand we offer, using the VegAuto Pump. Many people do use our convenient, robust 12/24V transfer pump, and "The Wand", to create a transfer and pre-filtering system. The Wand has a 70 micron metal mesh screen that removes for easy cleaning.
What do you mean by "experimental use"?
Plant oil as fuel should still to be considered "experimental" at this stage. WVO/UCO should be considered to be even more experimental than use of new cold pressed or food grade oil, since it's characteristics are more variable and harder to control.
We do NOT recommend use of plant oil as alternative diesel engine fuel for engines that are still under warranty, and it must be understood that most newer diesels are much more complex and sensitive than older designs.
That being said, tens of thousands of SVO diesels are now in use every day and many of these have operated for several years, some in excess of 100,000 km, without problems. A fuel standard (the RK Technical Standard) has even been developed in Germany for SVO, and an EU-wide fuel standard is under development. Plant oil as a fuel is a reality, and has moved well beyond the "backyarder/hobby/early adopter" stage.
With proper conversion components, installation, use and maintenance, and attention to oil quality, many users are currently experiencing excellent performance with minimal pre-treatment of the oil.
Some biodiesel advocacy groups, petroleum diesel suppliers, repair shops, manufacturers, academic researchers, and even some of the early adopters will sometimes be very critical of the use of plant oil as a diesel engine fuel. We ourselves have had a reputation for being among the most conservative of component suppliers and consultants. The reality is that diesel fuel and biodiesel can also create problems, and do, in some cases. As the old saying goes "anything can be done badly". Injection pumps wear on low sulphur and ultra low sulphur diesel fuel...it is a poor lubricant. This is well known. Biodiesel can be badly made. More than a low percentage blend of biodiesel can create gelling, filter blocking, fuel line and seal problems. This is also well documented. And yes, the improper use of poor quality plant oils in poor SVO systems can cause problems.
But, all these fuels can also be "done properly". Diesel lubricity additives and cetane improvers, etc. can improve diesel fuel. Biodiesel can be made to specification, filters changed, hoses and seals changed or monitored. Plant oil quality can be determined, and changes made to the fuel system, to minimize problems. SVO systems can be well designed and well built, and users educated.
Therefore, it is our position at this point in time that plant oil can be, and increasingly often is, a technically and economically feasible alternative diesel engine fuel. We base this not on wishful thinking or ignoring problems, but on the knowledge that we have gained from a number of years of personal use, research, and contact with customers, other component suppliers and with researchers who have taken the subject seriously.
How do emission, fuel economy and power compare with biodiesel and with diesel fuel?
Emissions results do vary between engines and test equipment, but in our tests on an early 80's VW turbodiesel, opacity (which is used as an indicator of particulate emissions) was reduced by about 50%, compared to premium diesel fuel. Other EPA regulated emissions were about the same for all the fuels tested. Power was equal to premium diesel that test. We find no difference power while driving, between diesel and SVO/WVO, as long as the filter is clean and the SVO is heated. See the section on emissions.
How long does it take to install your system?
Depending on the type of conversion and your level of skill and experience, conversions take 2-4 days.
Can I install it myself?
If you have moderate mechanical automotive wiring and fuel system skills, a willingness to learn and be patient, and basic tools, you can install our system. It is necessary to be very diligent and quality-conscious in the work, to follow instructions, to ask us if are having a problem. You may prefer to have a professional mechanic with diesel fuel system experience do the work for you, or have the components installed by us - in fact, we recommend one of those options.
How long does an order take to arrive?
Usual delivery time is within 2-3 weeks in the US. International orders can take longer. PLEASE note that if you are importing you will likely incur a cost for import brokerage and duty, and may receive a bill from the broker later. The amount varies by country. It is usually a small proportion of the cost of the items imported.
How do I order?
You can order our products online via secure server, from our home page. Some require that you provide some details. An email to us telling us of what you plan to do, the type of engine, where you plan to install the filter, etc. will also be helpful.
I understand you also are involved with biodiesel production... so, which is better, SVO or biodiesel?
As to biodiesel versus SVO, there really is no "better". You have to start with oil for both.
Some people enjoy the chemistry challenges of making biodiesel, and others prefer the more "mechanical" nature of SVO conversion. In fact, a lot of people do some of each, using "less suitable" oil to make biodiesel, and the better oil for SVO. Then they use the biodiesel for start/stop fuel in a two-tank SVO system.
No sulfur emissions (plant oils have negligible sulphur) = no acid rain contribution
Reduces soot (diesel smoke) 30-60%
Carbon dioxide emissions eliminated (LCA)
No global warming contribution (Plant oils capture the sun's energy via photosynthesis, and use carbon dioxide to grow - the CO2 is released again in a closed-loop, when the fuel oil derived from the seeds is burned)
Wide variety of local-derived sources - hundreds of plant oils worldwide
Recycles a waste - used cooking oil
Allows on-farm fuel production (using a small scale cold press)
Fastest Payback of any renewable energy
Easiest, least expensive "solar power"
Methods in use since 1999
Thousands of engines now on SVO
No chemicals, no processing, no capital investment in production facilities
SELECTING A DIESEL
CATEGORIES OF DIESEL ENGINES AND GENERAL SUITABILITY FOR SVO USE
Diesel engines Fall into one of several broad categories.
DIRECT INJECTION - "CLASSIC" TYPE
The first might be called the "classic" direct injection engine, as used in tractors, trucks, marine engines, generators, etc. for many decades. These were rugged, simple designs that provided lots of power (and pollutants) and were also relatively noisy - both of these things resulting from the fact that fuel was injected in "one shot" directly into the combustion chamber.
A number of studies and experiments involving the use of vegetable oils as fuel in these engines have been performed over the years. These studies most often did not pre-heat the oil, and did not use two-tank methods, and often did not use the most suitable oils. The results were generally discouraging, with a high incidence of "coking" of the injectors and other serious problems reported. It was the knowledge gained from this work that led to the focus on development and use of "biodiesel". It also led some researchers (professional and independent alike) to carry on with the study and use of straight vegetable oil, to see what might be done to resolve the issues (primarily coking/poor combustion) encountered. This has largely been accomplished. The most often cited reason for the continued interest is economic...it often costs less to use SVO than to make or buy biodiesel.
INDIRECT INJECTION (Pre-chamber) TYPE
Quieter and cleaner burning, but somewhat less efficient engines were developed for use in passenger cars, and other applications. These include the older Mercedes and VW engines, among others. The Mercedes engines up to 1999 are excellent for SVO use, having both "inline" injection pumps and an excellent pre-chamber design.
MODERN DIRECT INJECTION TYPE - COMMON RAIL, UNIT INJECTOR, ETC.
These are more recent, since the mid-nineties. Examples include the VW TDI, Ford Powerstroke, and most other modern diesels. They typically use mechanical or computer controlled injection that provides an initial, smaller shot of fuel directly into the combustion chamber, followed by the main injection of fuel milliseconds later. The result is an engine with all the power and efficiency of direct injection, but one that is quieter, cleaner, and *may* be at least as suited to SVO use as the indirect injection engines - although this is not yet established. These designs do emulate what happens in an indirect injection engine in some ways, and do operate at higher injection pressures, and do use more advanced glow plug systems, etc. - all of which bode well for SVO use. However, they also require fuel that is of higher quality and is even cleaner than ever!
The diesel fuel is often filtered to at least 5 microns (sometimes as low as 2 microns) in these systems, whereas in the older engines, 10 microns was most common. Higher injection pressures and closer tolerances and computers with viscosity sensors, etc. demand cleaner, higher quality SVO than older designs.
Planning an SVO Conversion
One of the first decisions most people face is which diesel they should obtain. Here are some general ideas to get you started on the decision process:
Car or truck?
If you do not need a truck, don't drive a truck (or SUV). You'll pollute less, and you'll need less fuel. That leaves more for the next person, supports the whole "sustainability" idea behind all of this, and on a practical level means that much less oil you will need to obtain, process, haul home, pre-filter, etc. and that many fewer jugs and cardboard sleeves (often this is the way you will get your oil) to be recycled.
Examining your real needs, and thinking seriously about this in advance can really help simplify the decision process and save you time and money later.
Let's say you decide that a car will work for your needs. The next item is a personal choice - how fuel-efficient do you want it to be? Generally, a 4 cylinder front wheel drive (e.g. a VW) is going to give the best fuel economy. 4 and 5 speed manual transmissions are also quite a bit more fuel efficient than automatics. It goes down the scale from there.
Front wheel drive does offer better traction in snow and ice. (Examples: VW cars are front wheel drive, Mercedes are rear wheel drive).
Four wheel drive can often give inexperienced drivers a false sense of security - the ability to go faster in snowy and icy conditions and maintain traction on a straight road does not mean that the vehicle will turn or brake any better, and often they don't handle very well at all when in four wheel drive (for example in skid). This overconfidence in four wheel drive in poor conditions, and the higher speeds that result are often cited as a factor in collisions. Very often, a good set of winter tires and a front wheel drive are as good or better, overall.
In a collision, the heavier vehicle usually fares better. A heavily built old Mercedes is probably going to do better in a collision than a lighter car of the same era in a collision, the penalty for weight, as always, being the need for more fuel. SUV's and pickups, despite their bulkiness, do not really provide greater protection than a well-engineered car, especially in a rollover. They do not handle as well and often do not brake as well as a car, and their higher center of gravity means increased risk of rollover.
The energy content of a given amount of vegetable oil is only a little less than that of diesel fuel, and is more than for gasoline. Therefore, power and fuel economy on SVO is almost the same as on diesel. Under most conditions, there is little or no perceptible difference to the driver between driving on diesel and driving on SVO.
SVO system reliability has improved greatly in a short period of time. The growing base of SVO users have contributed their knowledge to that gained in production and sale of systems. The SVO kit components are of high quality, and can be expected to work for many years. If you sell one vehicle, it is easy to remove the system (in less than a day), sell without it, and put in on your next purchase. Filter elements are readily available.
egtherm heaters use the most advanced solid state heating element technology available. Relays, circuit breakers and wiring are all oversized for the requirement. Screw terminals are used on the relay where needed and circuit breakers are sealed, waterproof, auto-reset type.
Fuel selector valves and Hotfox tank heaters are derived from equipment supplied to the heavy truck industry.
The transfer pumps we supply for tank filling are intended for oils up to the viscosity of gear oil, not diesel fuel pumps! They can better handle the thicker vegetable oils that will often burn out diesel fuel transfer pumps prematurely.
We kindly thank PlantDrive for using there FAQ text on this page. For more information about Biofuel conversion kits kindly visit the website from PlantDrive
Neoteric Biofuels Inc.
B.A.G. 9000 Suite 305
190 Trans Canada Highway NE
Salmon Arm, BC, Canada
FOR WASHINGTON, OREGON and CALIFORNIA ONLY, contact Craig Reece in Berkeley, CA.
Office/Online Hours: Monday-Friday 9 AM - 5 PM Pacific Standard Time
PLEASE use email for a *much* faster response. Please do not contact Craig unless you are in Washington, Oregon, or California. All other inquiries should be directed to the main email address above (Edward Beggs)
PlantDrive is the SVO division of Neoteric Biofuels Inc. © 2005 Neoteric Biofuels Inc.