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#1201: 20 Miles Per Wood Chip

Jan 07, 2012
This week on Car Talk, Hans recalls fleeing from Germany during World War II in a car powered by woodchips, but he's never been able to figure out exactly how it worked. So who better than two car experts with MIT degrees to figure this out? Well, maybe anyone would be better in this case. Tom and Ray will likely do better helping David figure out how a three-pound bag of Hershey Kisses disappeared from his Civic overnight, and why his car now smells of melted chocolate. Elsewhere, Victoria's Mom needs to trade in her Corvette after surgery, so Victoria's wondering what car's right for a hip Mom with a new hip; Aaron's windshield wipers are stuck in a salute position; and, is Mary-Ellen wearing out her brakes parking in "The Gulch" every day? A box of doughnuts is riding on the answer, so this is serious business. All this and lots more, this week, on Car Talk.

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30 Comments

Steam powered cars during WWII

When my father was stationed in the Philippines during WWII, they were running cars with a boiler in the trunk and piping steam pressure directly to the intake manifold. They had modified the timing gears to the cam to be a 1:1 ratio and were using the engine as a steam engine with a valve in the steam line as a throttle.
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Wood-Fired Vehicles

Most surprised that you had never heard of wood-fired cars. Actually, Vermont Castings, the wood stove company, retrofitted a bus to operate on wood back in the 1970s. Can be seen in some of their archival photos.
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The chumps got stumped at their own game.
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Car Running on Wood Chips

I grew up in Germany near Hamburg and recall very well that during the last year of WW II my father drove a gasoline burning car that had been converted to run on charcoal. The charcoal was burned with insufficient oxygen in a cylindrical barrel mounted on the rear bumper and the gas was then injected into the cylinders. (Wikipedia describes that wood chips were used for the same purpose as well, in Germany and other countries.) In February of 1945 my father was able to drove this car, pulling a one-axle trailer loaded with bags of charcoal, from Hamburg to a town near Berlin to rescue my aunt and her three sons before the Russians occupied that area. The only luggage they could take out was what would fit onto the trailer in the place where the charcoal bags that had been used up on the first leg of the trip. I used to help clean that combustion system periodically; it was a very dirty job!
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20 Miles Per Woodchip

MIT..? What does that stand for... Massachusetts Institute of Technology? They should make studying Mother Earth News part of the curriculum.... (http://www.motherearthnews.com/Green-Transportation/1981-05-01/Wood-Gas-Truck.aspx) I’m so disappointed… Hopefully Hans will have his faith restored after the next program…. Seriously you should look at this website. It has an interesting discussion and explanation of how a wood gas generator was built…Hmmm, I wonder if that would void the warranty on my Ford Diesel….
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Love every program...how do I get a cusshie job like that?
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wood gasification fail

devastated that 2 mit engineers are ignorant of wood gas internal combustion engines. keep google upn a laptop while taping, it will save you kiester.
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closing credits
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No-Brainer

Strange but true. Gasoline for civilian use was very limited during those war years and many places--Australia, New Zealand, UK, Germany, Austria, Sweden, Netherlands--used wood to run delivery trucks and farm vehicles. All gasoline was diverted for military use. I helped build a few of these woodgas generators for Mother Earth News magazine in the early 1980's for trucks, generators, and a sawmill. Newer designs have improved the technology.
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Wood burning (generator gas cars)

Woodburning cars were very commonly used in Sweden and Finland during WWII due to the extreme shortage of oil. You generate hydrogen and carbon monoxide by controlling the access of oxygen while burning wood chips. Most cars during the '40s were converted to this type by adding a "stove", usually in the back or trunk of the car. They are actually very effective, with 2000 lbs of wood corresponding to about 300 gallons of gasoline.
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Wood burning car engines

I was able to locate information on wwII wood burning vehicles. http://en.wikipedia.org/wiki/File:Planet_Mechanics_wood_gasifier.png and http://strangevehicles.greyfalcon.us/HOLZBRENNER%20VOLKSWAGENS.htm
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Woodchip Rerun

I knew I had heard this show clip before...this archived discussion: http://boards.straightdope.com/sdmb/archive/index.php/t-170133.html discusses Hans and his woodchips way back in 2002 or 2003, and also mentions the Geena Davis callback. Also, the listing for Episode 0305 on cartalk.com confirms Geena's call-in. So, when did they start inserting old clips into new shows?
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Still a great clip.
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Woodchip Rerun?

I swear that I have heard this Woodchip clip several years ago on Car Talk. I remember many of the details. And then, I remember the subsequent week Geena Davis (I think!) called up and said that her father had had this contraption or something, and the guys at that point had received the correct answer, and imparted it at the same time as she called. I vaguely remember that this clip was even online for a while as a "best of" kind of thing. So, is this a recorded clip?
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Still a great story.
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Wood Gasifier

If you'd like to check out a video of someone building and operating a standard gasoline engine on only wood chips, here is a link. It's from a Discovery Chanel show called 'The Colony'. http://youtu.be/VFQT3ya7BCQ
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Hip Mom's new hip needs a new car

My mother-in-law is short (5' 2" or so) and she needed a car where she could get in easy and sit upright and get a better view of the road. They chose the Mercedes Benz B200 and so far she's liking it. Only problem is that the car is higher maintenance.
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I haven't researched this with regards to cars, BUT...

..."oncet upon a time", I was experimenting with making black powder the old-fashioned way. One of the ingredients is charcoal, which I was *also* making myself. To do this, you can place wood chips in a *loosely* covered container, leaving a small opening, heat to the smoking point, and ignite the volatile gases that are emitted from the opening. Those gases burn like crazy, and the end result is charcoal. Hans mentioned two barrels, and a "draft" of sorts; I'd guess that the arrangement was designed to keep the wood smoldering rather than burning, and the volatile gases were then fed into the engine.
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Gotta be the mice, man! You guys suggested burning the car, and here I was just thinking "Palm it off on some unsuspecting buyer, then move without leaving a forwarding address..."
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#1201:20 Miles Per Wood Chip

He who knows a lot, my husband, said that the German trucks did run on wood chips. The engines were started with gasoline or kerosene and then ran on the smoke from the wood chips.
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All of them.
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WOOD BURNING CAR

Its true during the oil shortage during WWII, the german people would try anything to run their auto, and a german named Holzbrenner created a system for the VW, and GM ford and others looked into to it, norway has a festavial showing off this system and have one on a ford model t
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Caller #3 Victoria , mom needs new car.

I have leg and back issues and had to have a taller, more "chair-like" seat. I found it in the Buick Regal.I was able to raise up the seat to a higher level. I LOVE the sporty look and I got a beautiful brown and tan interior. The turbo option gives me power when I need it.
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Wood gas vehicles

I remember some years back reading from a car magazine in Finland how many of the cars and trucks were converted from being petrol run to burning woodring during the war time. More precisely, they were converted to run on carbon monoxide... Hans' recollection was correct. With a little research I found this website in English: http://www.energybulletin.net/node/51237
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Wood gas, gasogeno, or Holzvgas

A real Opel Blitz that runs on wood gas (Hotzgas in German) can be seen at this German museum: http://sinsheim.technik-museum.de/de/de/opel-blitz-3-lkw-mit-holzvergaser Or take a look at this 1:35 scale version: http://www.network54.com/Forum/47751/message/1316433911/Opel+Blitz+mit+Holzgas+-+1-35 http://en.wikipedia.org/wiki/Wood_gas_generator http://it.wikipedia.org/wiki/Gassogeno http://de.wikipedia.org/wiki/Holzgas
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Bo-o-o-o-gus!

I call bogus on the puzzler answer. You guys suggested that an ABS sensor could be used to detect low tire pressure because an under-inflated tire would cause the wheel to be smaller, and thus rotate faster in order to keep up with the other wheels. I don't think a properly inflated tire is appreciably stretched out like a balloon, so an under-inflated tire wouldn't actually be any smaller. The tread circumference doesn't decrease when the tire is low; it merely has more of it lying flat on the road surface. As a consequence, the distance to make the wheel go 'round remains the same, and a sensor looking for a faster wheel isn't going to find one, for this reason, anyway.
Favorite Moment: 
The moment I realized the need to call bogus on the puzzler answer.
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Wood Chip Engine WWII

Wood gas vehicles were used during World War II, as a consequence of the rationing of fossil fuels. In Germany alone, around 500,000 "producer gas" vehicles were in use at the end of the war. Trucks, buses, tractors, motorcycles, ships and trains were equipped with a wood gasification unit.
Favorite Moment: 
Stump the Chumps-sending this guy to look for a disconnected line after replacing his starter unit.
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woodchip cars

My dad talked about the potato sacks full of chips used to power cars during the war. Hans is exactly correct. How great to hear the story being told again
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Coal dust and wood chips

It looks like you've already received a few dope slaps about WWII era wood powered vehicles. Here's another slap regarding the use of coal dust as engine fuel. It was Rudolf Diesel (inventor of the Diesel engine), not Nikolaus Otto, who attempted to use coal dust as a fuel for internal combustion engines. BTW, I found the following about the wood chip fuel in a Mother Earth News article: "A German textbook I found on the subject states that a generator fueled with hardwood will produce a gas with a heating value of 1,250 kilocalories per cubic meter, consisting of 10.5% CO2, 0.4% CH, 1.6% CH2, 22% CO, 47.3% N2. The N2 and CO2 are non-combustible and contribute no power. Therefore, it helps if your vehicle has a big engine to start out with." Read more: http://www.motherearthnews.com/green-transportation/producer-gas-vehicles-zmaz74zhol.aspx?page=2#ixzz1ispJiFra
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Confusing Otto with Diesel.
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Opal Blitz

Gentlemen, This is in regards to the Opel Blitz wood burning truck. I am a student of military history, with the WWII Eastern Front being a specialty. While I do not doubt Han’s word that he witnessed this vehicle, I do question that this was a normal set up for the Opel Blitz. While your show was being aired, I had, in reach, my copy of the “Handbook on German Military Forces “ which was written for the US War Department in WWII, and has comprehensive information on all things German Army. Page 420, German Trucks Opel Blitz Type 3.6-36, Sub section Power. “The engine is a water-cooled, straight-size O.H.V. gasoline unit of 3.6 liters (219.6 cubic inches) capacity developing about 68 brake horsepower. The Gasoline tank (21.6 gallons) is situated under the driver’s seat…” Other trucks are listed, most gasoline, some diesel, none are listed as running on wood gas. Yours Phil Gardocki
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Wood Gas

www.soilandhealth.org/03sov/0302hsted/fema.woodgas.pdf FEMA likes it so if the government likes it, it can't be all that bad right? This illustrates how useful converting a carbureted engine to run on wood gas can be. It is not the most powerful but at least it works
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Surprised you didn't know about these

Wood burning cars are nothing new. There is a good article at http://www.lowtechmagazine.com/2010/01/wood-gas-cars.html I saw several wood burning cars in Holland/Belgium in the 60's - also some that burned wood to heat chicken droppings and other barnyard waste in a tank to create methane. These had a large pipe from the burner on the back over the top of the car to the engine compartment.
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Wood chip engine design/build

Details on wood chip engine: http://www.motherearthnews.com/Green-Transportation/1981-05-01/Wood-Gas-Truck.aspx
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Wood chip segment.
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20 Miles Per Woodchip

Great show, as usual. However, I'm surprised you didn't know that carbon monoxide is flammable. It is part of wood gas, along with hydrogen.
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Woodchips - it actually works !

Guys... Guys.. I loved Han’s call today on running a car on wood. Some friends and I actually made this work a couple of years back . We were on a Discovery Channel TV show called The Colony which was a post-apocalyptic survival show in which ten nutjobs (including yours truly) had to live in an old warehouse for two months . One of the challenges we had was to make electricity . We actually used the wood gassification method Han’s described to run a simple homemade generator. (see (http://www.youtube.com/watch?v=VFQT3ya7BCQ) Han’s memory was basically correct. When you do destructive distillation of wood in an airtight container you get a mix of many things. What actually burns is carbon monoxide (CO) and hydrogen (H2). There’s also a bunch of other things including steam, methanol and lots of volatile oils and tars whose main purpose is to gum up the engine over time J . Hope this helps ! Ps. Greetings from VoMIT.. Vermont’s own MIT club !
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You shoulda known this one!

Wood gas powered cars (converted petrol powered engines) were common in WWII when gasoline was in short supply (see lonk at http://en.wikipedia.org/wiki/Wood_gas_generator)
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Other suggestions for Hip Mom

I drive a Kia Soul. It also have higher seats than other cars. And it's hip enough :D Maybe she could also test drive it, and similar cars, like the Nissan Juke and Honda Fit :D
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Mice studies with infrared camera, ha ha.
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