What is Biodiesel?
Biodiesel is a vegetable oil-based fuel that runs in diesel engines — cars, buses, trucks, construction equipment, boats, generators, and oil home heating units. It’s usually made from soy or canola oil, and can also be made from
recycled fryer oil. You can blend it with regular diesel or run 100% biodiesel.
What are the benefits of using Biodiesel?
- No Engine Conversions. Biodiesel runs in
any conventional, unmodified diesel engine. No engine modifications are
necessary to use biodiesel and there is no engine conversion. In other
words, you just pour it into the fuel tank.
- Lubricates Engines. Biodiesel is more lubricating
than diesel fuel, it increases the engine life and it can be used to
replace sulfur, a lubricating agent that, when burned, produces sulfur
dioxide – the primary component in acid rain. Instead of sulfur, all
diesel fuel sold in France contains 5% biodiesel.
- Less Emissions. Biodiesel is nearly carbon-neutral,
meaning it contributes almost zero emissions to global warming. Since
biodiesel comes from plants and plants breathe carbon dioxide, there
is no net gain in carbon dioxide from using biodiesel. Biodiesel also
dramatically reduces other emissions fairly dramatically. Plus, the exhaust
smells like popcorn or french fries.
- Non-Toxic. Biodiesel is safe to handle because
it is biodegradable and non-toxic. According to the National Biodiesel
Board, neat biodiesel is as biodegradable as sugar and less toxic than
- Blends with Petroleum Diesel. Biodiesel
can be used alone or mixed in any amount with petroleum diesel fuel.
A 20% blend of biodiesel with diesel fuel is called B20, a 5% blend
is called B5 and so on.
- Safe to Transport. The flash point of a fuel
is defined as the temperature at which it will ignite when exposed to
a spark or flame. Biodiesel’s flash point is over 300° Fahrenheit,
well above petroleum based diesel fuel’s flash point of around
125° Fahrenheit. Testing has shown the flash point of biodiesel blends
increases as the percentage of biodiesel increases. Therefore, biodiesel
and blends of biodiesel with petroleum diesel are safer to store, handle,
and use than conventional diesel fuel.
- Good for national security. Since it’s
made domestically, it reduces dependence on foreign oil.
- Good for national economy. Using biodiesel
keeps fuel buying dollars within the country instead of sending it to
foreign countries. This reduces our trade deficit and creates jobs.
- No Storage Conversions. Biodiesel can be
stored anywhere that petroleum diesel fuel is stored. All diesel fueling
infrastructure including pumps, tanks and transport trucks can use biodiesel
- Good Performance. Engines running on biodiesel
run normally and have similar fuel mileage to engines running on diesel
fuel. Auto ignition, fuel consumption, power output, and engine torque
are relatively unaffected by biodiesel.
- Drivability. We have yet to meet anyone
who doesn’t notice an immediate smoothing of the engine with biodiesel.
It just runs quieter, and produces less smoke.
What are the disadvantages of using Biodiesel?
- Limited availability. Biodiesel not readily
available in much of the U.S. — yet. Here is a map of
biodiesel pumping stations. However, consumption of biodiesel
in the U.S. increases each year. Also, unlike other alternative fuels,
you can fill up your car with petroleum diesel in a pinch.
- Cold Weather Gelling. Like diesel fuel, biodiesel
can gel in cold weather. If you live in a very cold-winter climate, there
are simple preventative measures you can take. In fact, some diesel vehicles
come stock with cold weather equipment.
- NOx Emissions. The one emission that goes
up slightly with biodiesel is NOx (up to 15%). NOx contributes to smog.
Engine modifications can reduce NOx emissions.
- Biodiesel will clean your injectors and fuel lines. If
you have an old diesel vehicle, there’s a chance that your first tank
or two of biodiesel could free up all the accumulated crud and clog your
- Degrades rubber parts on older vehicles. Vehicles
manufactured before he mid-1990s might require upgrades of fuel lines
(a cheap, easy upgrade), as biodiesel can eat through certain types of
rubber. Almost all new vehicles should have no problem with biodiesel.
How is fuel efficiency (mileage) affected by biodiesel?
The fuel efficiency is the same for a petroleum diesel.
How are speed and power affected by biodiesel?
In tests done in U.S. universities and those in Europe, engines running on
biodiesel have minor, if any differences in torque, horse power, range, and
top speed. The experience with biodiesel users is that engines running
on biodiesel generally idle smoother and accelerate more smoothly.
Can biodiesel be produced in mass quantities — i.e. enough to
completely replace gasoline?
Yes. Biodiesel can be made in vast quantities from other sources
such as fast-growing, naturally occurring strains of algae. In Germany,
there is enough biodiesel produced to offer the fuel at over 1,300 service
stations across the country.
When was biodiesel first used?
Transesterification was conducted as early as 1853. Rudolf Diesel
designed this engine to run on vegetable oil. He did a demonstration at the
1900 World’s Fair where he ran his engine on peanut oil. One of the first
uses of biodiesel (transesterified vegetable oil) was powering heavy vehicles
in South Africa before World War II.
How much does biodiesel cost per gallon?
It depends where you live and the manufacturer — the cost
can range from $1.90-$3.50. For more details see the price
reports for alternative fuels.
What does it cost to make Biodiesel yourself?
If you make
biodiesel yourself, it costs about 60 cents per gallon to produce.
Most people use about 600 gallons of fuel a year (about 10 gallons a
week). Home-made biodiesel would then cost around $360 per year to produce
the 600 gallons (eleven 55 gallon drums of it). In comparison, gasoline
would cost $1122 per year at $1.87 per gallon.
Can I sell the biodiesel I make?
Generally, you are allowed to sell moderate quantities of biodiesel for “research purposes”, for example 2000 gallons a year. If you want to sell biodiesel commercially in the U.S., you will
need permits and you will need to charge road tax (about $0.45/gal).
I make biodiesel (from vegetable oil) to run my car. Do I have
to pay excise tax? If so what form or how would I pay it?
From the IRS: The
applicable diesel fuel tax rate is 24.4 cents per gallon. This tax is paid
by submitting Form 720 Quarterly Federal Excise Tax Return.
Biodiesel is considered as a blended diesel
fuel. The person that produces the blended diesel fuel, outside the bulk transfer/terminal
system (blender), is liable for the tax which is imposed under IRC section
4081(b) upon sale or removal. Blended diesel fuel is any mixture of diesel
fuel, with respect to which tax has been imposed and any other liquid(such
as kerosene)which no tax has been imposed. The number of gallons of blended
diesel fuel subject to the tax, is the difference between the total number
of gallons of blended diesel fuel removed or sold, and the number of gallons
of previously taxed diesel fuel used to produce the blended diesel fuel. An
exclusion from tax on the “blended taxable fuel” mixture is provided in Treasury
Regulations section 48.4081-1(c)(1)(ii) for minor blending if: during any calendar
quarter the removal or sale of the mixture in aggregate by the blender is less
than 400 gallons. The IRS Form is 720 and publication 510.
What about running your car on straight vegetable oil (SVO)?
You must convert each vehicle you want to run on straight vegetable
oil (SVO). This includes an additional tank for the oil plus special pre-heaters
and control systems. These kits cost about $800 plus labor. While this fuel
need no conversion to produce (unlike biodiesel), the oil must be of very good
quality. Many SVO drivers prefer fresh vegetable oil (FVO) over Waste Vegetable
Oil (WVO) to minimize hassles from the variables in using a waste product.
When it comes time to sell this converted vehicle, your buyer may not be interested
in running it on SVO.
I have a diesel engine car and I use straight vegetable oil to power the car.
Is the vegetable oil considered fuel and do I have to pay any tax on the vegetable
If the vegetable oil(straight oil with no mixture) is bought at retail and
you put it in your vehicle for personal use, there is no excise tax. If this
vegetable oil is mixed with other types of fuel and you have less than 400
gallons in any calendar quarter, it will be exempted from blended taxable fuel.
Vegetable oil(straight oil) per se is not considered as motor fuel or special
Will I void my car’s warranty by using biodiesel?
European diesel engines manufactured for the European market now come with
biodiesel-warranted engines. In Europe, Volkswagen, Mercedes, Volvo and
others are all warranted to run at 100% biodiesel. However, if you have
a diesel made for the U.S. market, you should check with the engine manufacturer
as to their warranty coverage. Some diesels in the US are now warranted
for use with biodiesel that meets the automobile manufacturer’s
fuel specifications. Most warranties state that any fuel system problem
caused by fuel that does not meet specs is not covered by the warranty,
however all vehicle-related problems are covered regardless of the type
of fuel used.
What adjustments should I make to my diesel engine before
- Retard the injection timing by 2-3 degrees — this overcomes the effect
of biodiesel’s higher cetane number. It also causes the fuel to burn
cooler, thus reducing NOx emissions.
- Petroleum diesel leaves a lot of dirt
in the tank and the fuel system. Biodiesel is a good solvent — it
tends to free the dirt and clean it out. Be sure to check the fuel filters
regularly at first. Start off with a new fuel filter.
- Check there are
no natural rubber parts in the fuel system. If there are, replace them.
Viton is best.
What are the details on protecting your car’s fuel lines in cold
Like diesel fuel, biodiesel can gel in cold weather. B100 (100%
biodiesel) gets slushy a little under 32°F. But B20 (20% biodiesel, 80%
regular diesel – more commonly available than B100) has a gel point of -15°F.
There are six different ways to keep a diesel vehicle’s fuel system
from gelling in winter. The use of a block heater at night and a tank heater
during the day has allowed biodiesel to be used in Yellowstone national
park down to -40 deg. F.
The six methods for keeping a diesel fuel system operational in winter
- An engine block heater to keep the engine warm at night. This helps
with starting on cold mornings.
- A fuel tank heater, which circulates coolant through a pipe in the
fuel tank. Any good diesel shop can install one.
- An electric element fuel line heater, which heats the fuel at one point.
- A coolant-operated fuel heater, which uses hot coolant and a heat exchanger
to heat a section of the fuel line.
- An electric fuel line heater. This is like an electric blanket for
the fuel line, which extends from the fuel tank to the fuel filter.
Winterizing agents and additives.
What are the best vehicles to use with biodiesel?
Notes from the Veggie
Van FAQ: We recommend vehicles with in-line diesel engines as opposed
to vehicles with V-6, V-8, or opposed cylinder designs. If you can find
an vehicle with an in-line diesel and a turbocharger, that’s even better.
The small surface area of main bearings and short throw distance of
rods in non in-line diesel engines limit their ability to take advantage
of the diesel’s efficiency and power. In the US, we recommend Dodge trucks
with Cummins engines, Volkswagen vehicles with TDI engines, and the Mercedes
Sprinter van with Mercedes TDI engine (this is sold through Freightliner
http://www.freightliner.com). If you are buying a used vehicle, by far
the best value for the money is a Mercedes car or station wagon. (A used
Volkswagen TDI vehicle is also an excellent choice – but difficult to
VW TDIs: Jetta, Beetle, Golf, mid-90s Passat, Pickup,
Mercedes diesels: (Sedans and wagons)
’81 to ’85: 300D, SD and SDL
Earlier: 300D and 240D
The 300s were 5-cylinder, later models with turbo, the 240s all 4-cylinder
Later: ’87 300TD wagon, 6-cylinder
’87 300SD (big body) sedan, 6-cylinder
190D, non-turbo 4-cylinder – later models may have turbo
’90’s – 300D sedans and 300TD wagons went back to a 5-cylinder turbo, 300SD
still had the 6-cylinder
524TD or 528TD, 1984-1985, 6-cylinder. Rare.
The same engine was used in the mid-’80s Lincoln Continental Town Car, also
The turbodiesel in the 505 sedans and wagons was a good engine, the non-turbo
in the 504 was pokey, all rare.
Nissan pickup (4×4 turbo diesel)
Volvo diesel car (VW 5-cylinder non-turbo and turbo)
Audi 5000 diesel 1979-83
Isuzu Imark car 1.8 liter
Isuzu PUP pickup truck 2.2 liter non-turbo and turbo
Mazda Pickup truck 1984 B2200
Mitsubishi Mighty Max Pickup truck
The infamous Oldsmobile diesel engines made by General Motors from 1978-1985.
The V8 5.7 liter was fitted to Oldsmobile sedans, Cadillacs and Chevrolets,
and some pick-ups.
The V6 4.3 liter was available in smaller front-wheel-drive vehicles, eg. Cutlass
Chevrolet car (3.5L)
Chevrolet trucks (6.2L-6.5L, Duramax diesel)
Chevrolet LUV (Isuzu pickup)
Chevrolet Chevette (1.8 liter Isuzu diesel engine)
Powerstroke diesel, from 1997 — direct-injection, electronic controls,
in pickups, vans, the Expedition, and the Excursion
Pre-1997: Ford/Navistar 7.3L V8, preceded by the Ford/Navistar 6.9L V8, both
Ford Topaz (Mazda diesel)
Dodge trucks (Cummings diesel)
Chevrolet Suburban 6.2 and 6.5 GM diesel
International Scout (Nissan diesel motor)
Isuzu Trooper 2.2 liter non-turbo and turbo
Toyota Land Cruisers imported from Canada.
Chrysler Jeep (diesels brought in from Canada)
Pre-74 Land Rovers, 4 cyl. 2.5 non-turbo diesel