# A Q about kerosone as fuel in old vehicles
**URL:** https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823
**Category:** Factual Questions
**Created:** [July 7, 2000, 4:01am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823 "2000-07-07T04:01:54Z")
**Posts on this page:** 17
**Page:** 1
### Author:  [@Shirley\_Ujest](https://boards.straightdope.com/u/Shirley_Ujest)
#### Post date: [July 7, 2000, 4:01am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/1 "2000-07-07T04:01:54Z")
Don’t ask me why I am asking this, I’m not sure why, but:
In old tractors (and big equipment) ( at least 50 years old) they use to run on kerosene. Somewhere along the way, they were switched the diesel. No modifications to the engines or what not, just changing the fuel. Diesel is now the norm.
Anyone here know the whens or ( what I’m getting at) the why’s?
How’s that for being vague?
---
### Author:  [@tcburnett](https://boards.straightdope.com/u/tcburnett)
#### Post date: [July 7, 2000, 4:42am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/2 "2000-07-07T04:42:31Z")
Why are you asking this?
Never mind. Research the difference between kerosene, #1 diesel and jet fuel.
As the metals in diesel engines bacame stronger and able to cope with high compression ratios (typically 16:1), they didn’t need as high an octane fuel. #2 diesel is cheaper.
---
### Author:  [@justwannano](https://boards.straightdope.com/u/justwannano)
#### Post date: [July 7, 2000, 4:58am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/3 "2000-07-07T04:58:33Z")
don’t know the answer but I am interested too.
I own a 1945 IH farmall H tractor which runs on gasoline. But the carburator looks like the one that was used in the distillate,another name for kerosene, engine.According to the operators manual it was a dual purpose carb. You first started it on gasoline and after a warmup period you switched to distillate.
It also says that a distillate engine may be operated on gasoline if necessary however more satisfactory results will be obtained when the engine is used with the correct fuel.
This is not a very powerful tractor by todays standards.We use it for mowing ,It’s really not very good at that even, and for running a elevator when putting hay in the barn.
My guess would be that as time went by they decided to specialize because they could get more power with the specialized engine.
---
### Author:  [@Gunslinger](https://boards.straightdope.com/u/Gunslinger)
#### Post date: [July 7, 2000, 5:32am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/4 "2000-07-07T05:32:01Z")
IIRC, kerosene, diesel, and jet fuel are different grades of the same thing.
semi related trivia: jet engines are cheaper to run than piston engines, because while piston engines use highly refined (expensive) 130+ octane AvGas, a jet uses cheap low-grade kerosene (jets will run on anything from salad oil to truck diesel, just not as efficiently)
---
### Author:  [@Mousseduck](https://boards.straightdope.com/u/Mousseduck)
#### Post date: [July 7, 2000, 5:44am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/5 "2000-07-07T05:44:54Z")
This is just a WAG, but diesel is less flammable than kerosene, so maybe they changed for safety reasons.
---
### Author:  [@justwannano](https://boards.straightdope.com/u/justwannano)
#### Post date: [July 7, 2000, 1:03pm UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/6 "2000-07-07T13:03:47Z")
I found this in an old enclylopedia copyright 1925and about every 2 years until 1944 then again in 1954
Ways are being sought to adapt the Deisel engine to motor truck service and perhaps to aeroplanes and automobiles.
and later
The diesel engine has been applied to railroad service,with spectacular results…Tractor powering by diesel is increasing.
---
### Author:  [@Coldfire](https://boards.straightdope.com/u/Coldfire)
#### Post date: [July 7, 2000, 1:09pm UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/7 "2000-07-07T13:09:14Z")
On a semi-related note:
A couple of army personel were fined here in the Netherlands a few years ago because it turned out they had been filling their cars with (stolen) aircraft kerosene. These were modern, petrol fueled cars that ran just fine on kerosene.
---
### Author:  [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)
#### Post date: [July 7, 2000, 1:20pm UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/8 "2000-07-07T13:20:19Z")
> [@](#):
>
> piston engines use highly refined (expensive) 130+ octane AvGas
There used to be 80 octane avgas, but I haven’t seen it in a while. The most common avgas (by my observation) is 100LL (“low lead”).
> [@](#):
>
> found this in an old enclylopedia copyright 1925and about every 2 years until 1944 then again in 1954 Ways are being sought to adapt the Deisel engine to motor truck service and perhaps to aeroplanes and automobiles.
> and later
> The diesel engine has been applied to railroad service,with spectacular results…Tractor powering by diesel is increasing.
There is currently a Diesel engine being developed for light aircraft.
> [@](#):
>
> Teledyne Continental Motors hasn’t designed and produced an all-new engine for quite some time. Older readers may recall the Tiara engine that was certified in the early 1970s but failed miserably in the marketplace. Chalking up the Tiara program as experience, TCM plans to take reciprocating engine technology to the next level with its yet-unnamed entrant in the GAP program. This 200-horsepower, four-cylinder, compression-ignition engine (don’t call it a diesel) will be a two-stroke design that to the uninformed will probably conjure thoughts of a smoke-belching behemoth that sounds like an outboard motor. Continental wants more than anything else to erase all that is popularly known about diesels and two-strokes.
>
> Through the use of the diesel cycle, the engine will not need spark plugs and will run on jet fuel, which has a far more certain future than does 100LL avgas (see “Future Fuels,” p. 59). The engine will also be liquid cooled to eliminate the potential damage caused by thermal shock and promote more even, controllable heat rejection. It is also hoped that controlled cooling will increase the time between overhaul (TBO) periods to intervals now seen only in turbines.
Source: [http://www.aopa.org/members/files/pilot/1998/engin9810.html](http://www.aopa.org/members/files/pilot/1998/engin9810.html)
---
### Author:  [@Shirley\_Ujest](https://boards.straightdope.com/u/Shirley_Ujest)
#### Post date: [July 7, 2000, 1:54pm UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/9 "2000-07-07T13:54:06Z")
Once again, I am astounded by dopers ability to take a half assed vague question and turn it in to something intelligent.
The reason behind my question was due to a buddy of my husband who found an old tractor on the back half of his property. Trees had grown up around the tractor and it was relatively protected for the last fifteen years or so ( since this friend owned the property) by the foliage. He decided to refurbish it and found it to be a 1920ish tractor that ran on kerosene.
That’s how the conversation started. I shall pass along the information.
Danke, dopers.
---
### Author:  [@honkytonkwillie](https://boards.straightdope.com/u/honkytonkwillie)
#### Post date: [July 8, 2000, 1:41am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/10 "2000-07-08T01:41:30Z")
All right - here’s your answer. Use ordinary diesel.
Kerosene and Diesel are very similar, but their true definitions are rather shifty, depending on the source. Fuels tend to have practical definitions rather than absolute, cookboook (take X amount of this and mix it with X amount of that…Voila! Diesel!) mixtures.
To a chemist, the difference is visible on a gas chromatograph. Diesel and kerosene are mixtures of several dozen major hydrocarbon species and a few hundred minor species, all within a more narrowly defined boiling point range.
Kerosene and diesel have maybe 90% of their compounds in common, with kerosene having some extra compounds on the light end (low boiling point) and diesel having extra compounds on the heavy end (higher boiling point) of the spectrum.
So, kerosene tends to weigh a bit less per unit volume, and consequently has a lower “energy density” than diesel.
The practical definitions arise from the refining process. To refine crude, basically, the thick black oil is slowly heated up and as the temperature rises, different compounds leave the liquid state and evolve in vapor state. This vapor is condensed and collected at certain intervals.
To collect diesel for example, you start to collect the vapors that evolve around 174°C (boiling point of decane, C-10) and stop collecting after you reach 391°C (boiling point of tetracosand, C-24). And you then have diesel, in which contains all the other compounds in crude that had boiling points \>174 and \<391°C.
So practically speaking, kerosene just has a slightly lower (and maybe narrower) boiling point range, say 120 - 300°C.
---
### Author:  [@tracer](https://boards.straightdope.com/u/tracer)
#### Post date: [July 8, 2000, 5:49pm UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/11 "2000-07-08T17:49:37Z")
So then:
[LIST=A]
[li]Where does gasoline fit into this picture?[/li][li]What’s the difference between diesel #1 and diesel #2?[/li][li]Why is diesel fuel given a “citane” (hexadecane) rating while gasoline gets an “octane” rating?[/li][/LIST]
---
### Author:  [@honkytonkwillie](https://boards.straightdope.com/u/honkytonkwillie)
#### Post date: [July 9, 2000, 10:05am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/12 "2000-07-09T10:05:59Z")
Gasoline is composed of compounds with a much lower boiling point range. Chromatographically, gasoline is defined as the fraction of crude oil with boiling points between C-6 (hexane) adn C-10(decane). Incidentally, C-8 is octane…remind me in a short while.
Chromatographically, diesel is from C-10 to C-24, or sometimes C-10 to C-28. It’s rather arbitrary.
Diesel #1 overlaps kerosene and diesel #2. Per volume, it is a little heavier than kerosene and a bit lighter than diesel. It’s claim to fame is lower vapor pressure and lower flash point. In colder climates, as winter sets in, gas stations serving diesel will switch to diesel #1 so that diesel engines will start, because #2 will freeze at not that cold of a temperature, and slush doesn’t flow too well. And of course, you get lower mileage 'cuz of the lower energy density.
Also, if you live in an area with lots of heavy truck traffic, you may have seen special diesel pumps containing “truck diesel”. This is a heavier grade of diesel which will make ordinary engines run really rough because it is so hard to ignite. Somehow, big truck engines are stronger or tuned differently, and they can get some awesome mileage from this usually cheaper stuff.
Now, the octane and cetane index thing. Do you know how the octane rating is derived? Well, octane, C-8 was chosen as the “average” gasoline molecule. Halfway between C-6 and C-10, intermediate boiling point and flash point, and whatnot. Of all the many compounds found in gasoline, it does a fair job of representing the whole mix.
So what they do to test a new batch of gasoline, is run the gasoline on a Knock Engine in a lab. As the fuel is sustaining the engine, they tweak the engine so it is running perfectly smooth with that fuel. Then, they switch to a synthetic fuel made up of heptane (C-7) and octane in some ratio, say 80% octane and 20% heptane.
When the new synthetic fuel hits the engine, it begins to run really rough since it is still tweaked for the real gasoline under test. Then, they start to increase the octane/heptane ratio until the knock engine smooths out again. If the engine became smoothest with 90% octane and 10% heptane, it is given an octane rating of 90.
A Cetane index is used for diesel 'cuz cetane (C-16) is a good representative molecule for diesel fuel. I’m not sure what the other component of the synthetic fuel is, maybe C-15 or C-14. But the same type of test takes place: tune engine to mystery fuel, adjust ratios of synthetic fuel to obtain the same performance, and call it good.
The real beauty part of this, is that it doesn’t really matter what the fuel producer uses to make diesel with. As long as it passes the battery of tests, it can be called diesel. Tests like water content, sulfur content, boiling point, flash point, density, color, BTUs, vapor pressure and many others.
---
### Author:  [@Chas123456789](https://boards.straightdope.com/u/Chas123456789)
#### Post date: [July 9, 2000, 9:22pm UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/13 "2000-07-09T21:22:54Z")
My Father had a couple of old Tractors which had been used for various things including driving sawbenches. Both could be started on Petrol (Gasoline) and switched to Paraffin (Kerosene) when warmed up. The Fordson had been modified to do this I think but the older International (Now International Harvester I guess) had some kind of valve near the carburetter and if memory serves me right a “Vapourisation Pipe” which went round the exhaust manifold to preheat the Kerosene. The reason for this apparently was simply one of cost. Kerosene in those days was much sheaper than gasoline. With or without preheating the mixture was hardly well controlled so they would use a lot of fuel and smoke like hell but in those days nobody cared. We also found a small static engine which would run on gas, kerosene or whiskey. We found this performed best if you drank the whiskey before starting it.
By the way these were HAND CRANKED so you switched back to gasoline BEFORE stopping the motor, else you had to hand crank the kerosene through and clean the plugs!
---
### Author:  [@SarumanRex](https://boards.straightdope.com/u/SarumanRex)
#### Post date: [July 10, 2000, 11:22pm UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/14 "2000-07-10T23:22:59Z")
\*quotes in italics were originally posted by honkytonkwillie \*
I don’t mean to nitpick but my chemistry textbook (Chemistry, The Central Science by Brown, Lemay, and Burstein 6th ed.) has a thing or two to say about gasoline and some of it contradicts this previous post, so in the interest of getting the facts to the teaming millions I thought I’d post my info:
_Chromatographically, gasoline is defined as the fraction of crude oil with boiling points between C-6 (hexane) adn C-10(decane). Incidentally, C-8 is octane…remind me in a short while._
Almost correct, according to my text “straight run gasoline” is a distillate of petroleum with boiling points from 30 to 200 degrees Celcius, C[sub]5[/sub] to C[sub]12[/sub].
\*Now, the octane and cetane index thing. Do you know how the octane rating is derived? Well, octane, C-8 was chosen as the “average” gasoline molecule. Halfway between C-6 and C-10, intermediate boiling point and flash point, and whatnot. Of all the many compounds found in gasoline, it does a fair job of representing the whole mix.
So what they do to test a new batch of gasoline, is run the gasoline on a Knock Engine in a lab. As the fuel is sustaining the engine, they tweak the engine so it is running perfectly smooth with that fuel. Then, they switch to a synthetic fuel made up of heptane (C-7) and octane in some ratio, say 80% octane and 20% heptane.
When the new synthetic fuel hits the engine, it begins to run really rough since it is still tweaked for the real gasoline under test. Then, they start to increase the octane/heptane ratio until the knock engine smooths out again. If the engine became smoothest with 90% octane and 10% heptane, it is given an octane rating of 90.\*
Again this is almost correct, here is what my textbook has to say:
> [@](#):
>
> The octane number of a gasoline is a measure of its resistance to knock. Gasolines with high octane number burn more smoothly and are thus more effective fuels. The more highly branched alkanes have higher octane numbers than the straight-chain alkanes. The octane number of gasoline is obtained by comparing its knocking characteristics with those of “isooctane” (2,2,4 trimethylpentane) and heptane. Isooctane is assigned an octane number of 100, whereas heptane is asigned 0. Gasoline with the same knocking charcteristics as a mixture fo 90% isooctane and 10% heptane is rated as 90 octane.
> The gasoline obtained directly from fractionalization of petroleum (called straight-run gasoline) contains mainly straight-chain hydrocarbons and has an octane number of around 50. It is therefore subjected to a process called cracking, which converts the straight-chain alkanes into more desirable branched-chain ones.
The reason I am posting all of this is because most people think (as I used to) that pure octane is the best fuel and has an octane number of 100. In fact, pure 2,2,4 trimethylpentane has an octane rating of 100 and would kick ass as a fuel, pure octane would suck ass as a fuel.
octane: CH3CH2CH2CH2CH2CH2CH2CH3
2,2,4 trimethylpentane:
C[sub]|[/sub]H3 C[sub]|[/sub]H3
CH3CCH2CHCH3
C[sup]|[/sup]H3
---
### Author:  [@honkytonkwillie](https://boards.straightdope.com/u/honkytonkwillie)
#### Post date: [July 12, 2000, 8:33am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/15 "2000-07-12T08:33:03Z")
Saruman - Thanks for the clarification on those two points.
I don’t feel too out of line by saying gasoline is C6-C10, as diesel is commonly defined as C10-C24, or C10-C28. There’s bound to be some overlap in all of the different fractions removed from crude oil.
You are absolutely right with the octane/iso-octane thing. I should have caught that myself. It was a detail that I lost over time from not using this knowledge for a while.
Incidentally, there are octane ratings higher than 100. Most of the information I gave was obtained form an old and out of print ASTM manual on petroleum product testing or something. It described the isooctane/heptane ratio thing like we already have up to 100, but they used a different reference for the higher octane ratings. I’ll be damned if I can recall what it was.
You got me thinking about the common (mis)perceptions regarding the cost/benefit of using high octane fuel in your car. It seems like Consumer Reports, et.al. annually remind consumers that “it is a waste of money…no added benefit, …cars run JUST FINE on 87 octane…”. Yeah, right.
Me and millions of others notice a difference. I think I’ll start a thread about this.
---
### Author:  [@Coldfire](https://boards.straightdope.com/u/Coldfire)
#### Post date: [July 12, 2000, 9:47am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/16 "2000-07-12T09:47:57Z")
Here I am, with another semi-related note.
My father currently drives a diesel car (Peugeot 406) and has done so in the past as well. In the winter, it is customary to add a few liters of normal petrol (or gasoline, for you Yankees) to a full tank of diesel. Supposedly, this makes it easier for the car to start.
---
### Author:  [@Jvanhorn](https://boards.straightdope.com/u/Jvanhorn)
#### Post date: [July 12, 2000, 10:02am UTC](https://boards.straightdope.com/t/a-q-about-kerosone-as-fuel-in-old-vehicles/24823/17 "2000-07-12T10:02:14Z")
I think that it’s possible that what Shirley is referring to is a Rumely Oil Pull tractor. This was one of the tractors that my grandfather used for a long time.
I know that it used kerosene for fuel, but I have often wondered myself exactly what the mode of operation was. Looking at the old pictures, it looks almost more like a steam engine than an internal combustion engine. Does anyone know which is the case? My Dad doesn’t remember the tractor either, and Grandad died before I got to ask the question.