Horse power calculator 0-60 mph

Here is a link to a horse power calculator that Chris found .

It is a test of horse power 0-60 mph.

I don’t think it will work for gasified vehicles unless we add some factor to the results to consider the gasifier starting from a dead start. The gasifiers have very little of its power reserve compared to the power at cruising speeds.

Below is a link to the calculator.

Below are some test of four different trucks. I let them all idle a short time before stating the test as to imitate a stop sign or red light.

The road has about 4-6 feet down grade at the end of apx ¼ mile.

The times are an estimation from viewing the video, also the weights are estimated .

#1 V-10 dodge ram 4WD apx 8000 lb 26 sec 86 hp

#2 V-10 Dodge Ram 4WD apx 13000 lb 40 sec 78 hp

#3 V-8 93 dakota apx 4800 lb 30 sec 42 hp

#4 V-8 93 dakota apx 4800 lb ( different truck from above ) 26 sec 51 hp

#5 V-8 92 dakota apx 4200 lb short cab 22 sec 56 hp

#6 is the above truck before gasification and on gasoline 3800 lb 10 sec 144 hp

I think the best power test will be 40 mph to around 70 mph to give the gasifier the benefit to make a little gas.


Very true Wayne. My cavalier did very well in the parade today (it was raining) and then I went for a nice drive in the country to stoke it up and clean it up and use up the wood. I stalled in the intersection in town at the top of the hill and the announcer said I had run out of wood. Problem was I was running hybrid right then and it flooded on gasoline. I ran my diagnostic monitor the whole time and it was interesting to see how the timing was adjusted. I’m a happy camper regardless because all ran perfect after the parade so I cured the other problems it all had. Grate had a lot of deposits on it that I cleaned off with a threaded rod and there was another big rot hole in the cyclone … 30 to 60 would be a better range to fudge us small car guys in. I can’t drive 70 anywhere within 8 miles of here without piggy getting me … There are more pigs than people that walk anymore … Mike

Hi Wayne,

I retimed a few of those, you were a tad optimistic, particularly on #3. I count from the time the foot goes down and revs begin rise to the time 60 shows on the speedo or is called out. Looks like 40-50 HP on the dakotas and 70 HP on the Ram. Later gasifiers have steadily improved in HP.

The Horsepower calculator is mostly telling us what we already know; there’s not much reserve power available at a dead stop. But the gasifier catches up quickly, and can maintain nearly double that starting horsepower.

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Sent this to Wayne a while back. Has some rough estimates on power production from his units.


I have been working through the theory that gasifiers should be rated for X amount of horsepower, regardless of the application. I get this based on the facts that:
Gasifiers don’t know what you’re using the gas for, all they know is how much you’re pulling
There is a certain amount of gas that the unit will reliably provide before it overheats.
The BTUs from that gas translate directly into horsepower, more or less depending on the engine efficiency/compression.
This horsepower rating is similar to a duty cycle, may be temporarily exceeded on some designs but must be respected in the long term
Running with a lighter duty cycle is good for the unit and provides a reserve of power.
So I set off to determine how much HP Wayne’s unit is making. With no scientific tests I have to go by the anecdotal evidence. Used the calculator here:

Notes: Frontal area is the profile of the vehicle seen from the front. Basically height times width. CD is coefficient of drag, and tells you how aerodynamic or “slippery” your car is. Smaller number is better. Trucks are not very aerodynamic, so we get high numbers like .90 for full size trucks.

12"x18" firetube:
Dakota with frontal area ~ 40 sq ft and CD .70 weighs 4,000 lbs, @ 55 MPH requires 39 HP. Estimated duty cycle 40%, max 100 HP
Dakota with frontal area ~ 40 sq ft and CD .70 weighs 4,000 lbs, @ 75 MPH requires 91 HP. Estimated duty cycle 90%, max 100 HP
D250 with frontal area ~48 sq ft and CD .90 weighs 5,000 lbs @ 55 MPH requires 59 HP. Estimated duty cycle 62%, max 95 HP (less HP with older engine)
D250 with frontal area ~48 sq ft and CD .90 weighs 5,000 lbs @ 65 MPH requires 92 HP. Estimated duty cycle 96%, max 95 HP
12x22" firetube:
Dodge V10 with frontal area ~55 sq ft and CD .90 weighs 7,000 lbs @ 65 MPH requires 108 HP. Estimated duty cycle 90%, max 120 HP?
Dodge V10 with frontal area ~55 sq ft and CD .90 weighs ~15,000 lbs (hay on trailer) @ 60 MPH requires 104 HP. [Same duty cycle but accelerates much slower due to heavy load. On country roads with lots of stops duty cycle may increase due to constant starts and stops, but top speed will be lower to compensate.]
Amazing comparison 75 MPH vs 55 MPH. Over double the HP required. Also explains why nearly every design seems to hit 50-55 but very few go 75 on the freeway.

Accelerating takes a LOT of HP. According to the calculator here:, my gasoline test of 15 seconds 0-60 translates into 117 HP, and the engine is rated 140, so that checks out. To get 30 seconds 0-60 (typical woodgas acceleration) only takes 40 HP. Definitely not the full capacity of the gasifier. If I were able to harness all 90 HP, times would be around 18 seconds. Wayne should be able to hit 14 seconds in the Dakota. Something else is going on, obviously the gas isn’t there yet and the engine is not able to spin up fast enough because it’s busy pulling on a gasifier. Like taking a deep breath through a straw. Takes a while!



Hey Chris,

My counting may be a little like the guy parachuting form a plane that stuttered real bad. It got him into trouble also.

He was told to count to ten and pull the rip cord.

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The duty cycle will vary depending on what gear you run in. I can get to 75 mph in 4th gear and stay there for along time as the duty cycle is about 60%. [I think] Once I hit 5th gear the speed begins to slowly fall and the duty cycle goes up to 100%. We saw this when we hooked up the laptop to the truck as we were running. I am happy with 65 mph in 5th gear on the highway. If I get behind a semi trailer I can run 70 mph in 5th gear. Gas temp stabilizes at 350 C at the gasifier and runs about 200 F out of the heat exchanger.

When running on the highway my wood consumption goes up a bit. I yesterday I burned 70 lbs. over 120 miles. I normally burn way less at 50 mph.

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Hi woody
That’s really interesting
do you run an 18" WK style gassifier?
My time doesn’t allow me to get on here much and i miss a lot
I have all the stuff to build a small 8" wk style for my gen set but i want to do my old nissan as well but for now i can’t do anything but gather parts

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Considering the calculator was set up for liquid fuel, I think a more accurate method would be to have a temporary storage of WG to use so there will be no lag time in the gaser.This my show an increse in HP. I seen some photos of an old bus in europe that was fitted with a rubber storage container,the totat area of the roof & a cuople feet thick. I belive the artical said this was to avoid pasengers from getting burned. The gasser was stationary & the bus refueled as needed.

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I use a little bit different setup than Wayne does. His 18 inch should do though. I found a small gasifier much more challenging than the larger ones. For one thing the fuel prep drove me nuts. Sizing of the chunks was critical.


Nice thread here.
Woody, respectfully… I think the duty cycle in 5th gear is going the other way… the RPM drop is causing the engine to stoke the gasifier less, resulting in a drop in production, or a lower duty cycle. The engine RPM seems to be one of the keys to the ultimate output you can get from a gasifier… Could your truck drive the duty cycle to 100% in 4th if not for redline of the engine (the air pump driving the gasifier).

I am glad to see everyone taking notes and making measurements in a uniform way to help gauge WG performance. The HP calculator is spitting out an average HP for the 0-60 run. I think that the aerodynamic drag increases exponentially, so that is why the HP needs increase at higher speeds. I like the time measurement and calculator as a tool, or indicator, or point of reference, so…

I decided I would try something in my gasoline powered Dakota to (since I don’t Drive on Wood (yet)). The plan is to compare a gearing change on a gasoline engine to see if there is a difference in the average HP stated by the calculator. We all know there has been no engine or fuel modification, but would there be a resulting difference in HP ?

My 4x4 Dakota has a dual range transfer case, 4 low and 4 high. I had planned to do a 0-60 pass in 4 high as a baseline, and then make another 0-60 pass using 4 low, then plug the numbers into the calculator. However, there may be an issue with my 4 low, because the light blinks when I switch it to 4 low. (is this normal?) It pulls like the lower gear set is working, but I am not ready to throw caution to the wind and tach it out in 4 low if there may be a problem…The other thing is I think the owners manual and common sense sez to keep it below highway speeds in 4 low. Anyone ever drive 60 using 4 low ? I could look for a 0-40 MPH calculator alternatively…

The point I am trying to prove (or dis-prove) is that a vehicle with the same engine, and same fuel, but with different gears may get you different times in the 0-60, and could result in a different average HP in the calculator… I do not know enough about it to say how much difference, but would imagine the lower gears will give you higher HP numbers unless the engine cannot rev high enough because of some other limitation like exceeding the redline trying to get to 60 in top gear…

I am also curious about the chicken and egg aspect of the engine driving the gasifier to make the fuel for the engine to spin faster to make the gasifier work harder to make more fuel…Once this has been repeated up to the top speed (100% of output) is the system limited by the speed of burning so much wood at a time or something like n pounds per minute? Is this where there is a concern of overheating the unit, or is it when the gasifier is running low on fuel, or both ?

Woody, respectfully… I think the duty cycle in 5th gear is going the other way… the RPM drop is causing the engine to stoke the gasifier less, resulting in a drop in production, or a lower duty cycle. The engine RPM seems to be one of the keys to the ultimate output you can get from a gasifier… Could your truck drive the duty cycle to 100% in 4th if not for redline of the engine (the air pump driving the gasifier).


I probably used the wrong term. The laptop program ran real time while we ran on wood gas and one of the measurements showed “engine load” The load on the engine is 100% in 5th gear. All this did was confirm what the books say about gearing down to get more speed. The downside is, more rpm’s. This puts more wear on the engine and heats up the gasifier in most cases. Thanks.

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Ahhh, OK, so the load represents all the torque the engine can produce on the fuel that it is being fed. Lower gears improve torque at the expense of higher engine RPM.

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I found something that I bought back in 1994 … a little performance computer thingy about the size off a radar detector. It is called a G-tech Pro by Tesla, and I have since lost the operation manual, but basically you plug it in, get it into input mode and tilt it to enter the vehicle weight, then stick it to the windshield, and make sure it is perfectly level and that you are on a nice level road with no wind, etc and zero the meter out. Then HIT IT ! it gives you the instant G force or time for 0-60 or for the 1/4 mile and posts HP numbers too. Here is the site where the show a picture of the 1994 model that I have (it is discontinued) and all the new stuff they have:

I started poking around for documentation and found a nice techie document on measuring HP, and it encourages making several runs and practicing consistency, etc… They say there are a lot of variables, so I can only imagine how long the equations would get to include a gasifier system in them. Anyways, to see their tips on measuring HP and TQ, see

I compared the device to 1/4 mile time slips from a race track in my car project back in 2001 - a 1980 Mazda RX7 with a 460 Big block from a farm truck…

For simplicity and uniformity, I think I like the idea everyone is using on this DOW site…just tape a few runs on a safe, level stretch of road with a video camera and when back home, type in a few numbers on a web page. Mush easier than all this variability, but theres lots of interesting info about how aero drag comes into play and the power band, etc if you like to read.

This morning I gave the 92 dakota another try at the 0-60 test.

I found a lose connection on the gas delivery piping that had been pulling in a little air and tighten it but I think it had little effect on the acceleration.

Looking at the video it appears that 0-60 is going to be between 20-22 sec.
For what it is worth my GPS reads 60 mph when the speedometer is reading 59 but I forgot to hook it up this morning and was reading the speedometer.

Sorry about all the MMMMMMMMMM before I said mark.

The gasifier was at operating temperatures and I didn’t let it set before acceleration.

An acceleration test from a dead start is not a good power test for a gasifier but it will give us some figures to cerate a base line.



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Wayne, You keep this up and someone is going to beat you. That was a good time on the 0-60 … ML
PS, I think you would enjoy this cavalier when it works right … Still looking for a small pickup with the 2.2 liter and stick so I can just set all the stuff in the back instead of a trailer …

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Here is an old thread I brushed the dust off and bumped up to the front . May be good reading for a cold winter day if you don’t have anything else to do :neutral_face:

Edit . The main interest would be Chris’s calculations


That was some great reading Wayne. Thanks, I ejoyed it very much. I wasn’t even a member back in 2012, I had heard of the gasifers in world war two and something in Mother Earth New magazine, but that was about it. What a difference in what I know now about DOW and other gasification related topics. It has been a great learning adventure with you all. Thank you.


Very interesting reading for sure.

I wonder how much difference it would make to do several 0-60 in a row, with as short stops as possible inbetween. Gas made slowing down (idle) with a really hot gasifier is obviously richer (made with excess heat and low on nitrogen).

I think I’ll be doing some DOW testing :smile: