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Author Topic: What is the difference between diesel fuel and petrol (gasoline)?  (Read 128224 times)

Offline scanner

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If ewer happy then sow are we.
 

Offline lightarrow

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Please supply a link to any information that NOX is carcinogenic as that is news to me and I have never heard it suggested anywhere else than in this forum.
In fact a google turns up this reference
Quote
   
How likely are nitrogen oxides to cause cancer?
The Department of Health and Human Services (DHHS), the International Agency for Research on Cancer (IARC), and the EPA have not classified nitrogen oxides for potential carcinogenicity.
that took all of 2 seconds to find..................and if THEY especially the EPA can't find a link how can you?
You really do need to take your, blinkers off and get real. Stating LIES as facts just shows you up as misinformed and muddle-headed.
And just so you know, petrols also produce uncombusted hydrocarbons not only diesels, so don't try that form of smearing to try and make your weak and unsubstantiated case stick either.
Diesels pollute, but petrols pollute more simply because they produce much more exhaust volume from a more polluting fuel.
I think you should go away and do some up to date "sampling and studying" before sharing your "knowledge" with the world.

NOx reacts with amines in biological compounds/tissues forming nitrosamines, which are powerful carcinogens:

http://en.wikipedia.org/wiki/Nitrosamines
 

Offline lightarrow

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I also would like to precise something:
1. I certainly don't say petrol engines don't pollute; infact I said that, in case, I would prefer alcohol engines (not hydrogen because it would need a lot of energy and so pollution, to get it).
2. I'm not against all diesel engines in general, but against most of the existing ones, because most of vehicle's pollution comes from them (especially lorries, I presume), for example HC, NOx and particulate. Of course petrol engines also produce a huge amount of pollution, but most comes from existing diesels, because most of them are not modern engines (Euro 4, Euro 5, with antiparticulate filters ecc.).
3. In no way I have an interest in imposing my beliefs; I'm only expressing my ideas, which comes from what I have get through different kinds of information means; if they will result to be wrong, I will accept it; it wouldn't be the first time I have something to learn, and a Forum is exactly a place and a mean to exchange ideas and informations. Isnt'it?
 

Offline scanner

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So now you claim NOX MAY be a carcinogen IF it reacts with something else - MAYBE.

That is not what you stated as FACT earlier.

Diesels may produce most pollution and it may be the bigger ones that produce most - trucks etc - BUT can you imagine the pollution if all those trucks had petrol engines? What is your alternative to that?

Alcohol may be a good idea but have you studied just how much energy is needed and how much pollution is caused by it's production?
Bio-diesel is far cheaper and easier to produce and produces far more energy at far lower cost. The huge boom in diesel ownership in recent years (certainly in the UK) means that most diesels are less than 3 years old. If all the older ones are to be scrapped think of all the pollution produced when their replacements are manufactured and all the pollution involved in disposing of them.

Pollution produced by use of a car (whatever sort of engine it is fitted with) is relatively small compared to manufacture and disposal.

It is for this reason that hybrids like the Prius are very "UNGREEN" because of the huge extra pollution involved in making and disposing of their battery packs every few years.
« Last Edit: 19/02/2007 17:01:15 by scanner »
 

another_someone

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Pollution produced by use of a car (whatever sort of engine it is fitted with) is relatively small compared to manufacture and disposal.

It is for this reason that hybrids like the Prius are very "UNGREEN" because of the huge extra pollution involved in making and disposing of their battery packs every few years.

The battery packs on the prius are Nickel Metal Hydrides, which are still cleaner to dispose of then the lead acid batteries on conventional cars.

I am not sure where you get the idea that the batteries have a short design life, although NHM batteries inherently have a problem with high levels of self discharge, and so can present problems with vehicles that are infrequently used.  I believe the Toyota will be moving to Lithium Ion batterry technology in 2009, which has far less of a self discharge problem.

The other advantage that has not been mentioned about hybrid and electrical cars is the use of electrical (regenerative) braking.  Aside from the energy efficiency this introduces, it also reduces the amount of brake dust generated - which itself is a pollutant.

Ofcourse, all of this depends on the type of driving you are doing - and if you are doing the kind of driving that inherently requires little braking, then this is not an issue.
 

Offline lightarrow

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The other advantage that has not been mentioned about hybrid and electrical cars is the use of electrical (regenerative) braking.  Aside from the energy efficiency this introduces, it also reduces the amount of brake dust generated - which itself is a pollutant.
Ofcourse, all of this depends on the type of driving you are doing - and if you are doing the kind of driving that inherently requires little braking, then this is not an issue.
However, the energy lost by acceleration/braking is infact quite a relevant amount of the total energy used, for a car, so the use of electrical braking would considerably reduce a car's fuel consumption, in my opinion.
 

Offline lightarrow

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So now you claim NOX MAY be a carcinogen IF it reacts with something else - MAYBE. That is not what you stated as FACT earlier.
NO and NO2 are free radicals. It means: very reactive compounds.
Quote
Diesels may produce most pollution and it may be the bigger ones that produce most - trucks etc - BUT can you imagine the pollution if all those trucks had petrol engines?
Yes, I can imagine it: much less particulates, less HC and NOx. Of course this wouldn't exactly mean pure air, but certainly a little bit better.
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What is your alternative to that?
Alcohol may be a good idea but have you studied just how much energy is needed and how much pollution is caused by it's production?
Not very much, using cellulose fermentation.
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Bio-diesel is far cheaper and easier to produce and produces far more energy at far lower cost. The huge boom in diesel ownership in recent years (certainly in the UK) means that most diesels are less than 3 years old. If all the older ones are to be scrapped think of all the pollution produced when their replacements are manufactured and all the pollution involved in disposing of them. Pollution produced by use of a car (whatever sort of engine it is fitted with) is relatively small compared to manufacture and disposal.
Are you saying that if we have poisonous things the best solution would be to keep them and keep us poisoned? It's a strange way of thinking! (And I'm not referring to diesels only, but to things in general).
 

Offline scanner

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You seem to be one of the few people who think NOX is so dangerous in the concentrations produced by diesels and indeed that diesels are a major source. I reckon more NOX is produced by cigarettes and more directly ingested (i.e. straight into the lungs)than from diesels.

Yes and much more Benzene, much more sub-PM10 particulates, much higher overall volume of emissions, more Co, shorter engine life with earlier/higher combustion of lubrication oil causing more smoke, much more rapid exhaustion of a finite resource.

Huge areas of land and enormous distillation plants would be needed to produce enough fuel for thirsty spark ignition truck engines.......... you really cannot be serious, as somebody once said and I still hold that the dangers inherent with making and transporting alcohol are not worth the risk, just one bad accident could kill more people in one go than in years of use.

Whole life costs! You cannot just count "use" toward whether something is "good" or "bad" you have to count from making it to disposing of it as well. The ill effects of getting rid of an old one and making a new one can easily outweigh the ill effects of using one that is maybe not quite as "good" as it could be.

So diesel is now "poisonous" is it - just what is petrol then?
 

another_someone

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However, the energy lost by acceleration/braking is infact quite a relevant amount of the total energy used, for a car, so the use of electrical braking would considerably reduce a car's fuel consumption, in my opinion.

In urban traffic, this is certainly the case; but I think one of the reasons why the Prius has proved a little disappointing for some (although it is still very early in the evolution cycle for that technology) is that the same does not hold true for long motorway drives, and it depends upon the type of driving you are doing as to how significant regenerative braking would be.  For Americans in particular, who in may parts of the country don't even have much in the way of bends in the road, and they can just drive on cruise control (something that would be considered highly dangerous in most of Britain, especially the south-east), the benefits of regenerative braking would be marginal at best.
 

Offline lightarrow

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In urban traffic, this is certainly the case; but I think one of the reasons why the Prius has proved a little disappointing for some (although it is still very early in the evolution cycle for that technology) is that the same does not hold true for long motorway drives, and it depends upon the type of driving you are doing as to how significant regenerative braking would be.  For Americans in particular, who in may parts of the country don't even have much in the way of bends in the road, and they can just drive on cruise control (something that would be considered highly dangerous in most of Britain, especially the south-east), the benefits of regenerative braking would be marginal at best.
Yes, I forgot that in America, everything is different!
 

Offline lightarrow

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You seem to be one of the few people who think NOX is so dangerous in the concentrations produced by diesels and indeed that diesels are a major source. I reckon more NOX is produced by cigarettes and more directly ingested (i.e. straight into the lungs)than from diesels.

Yes and much more Benzene, much more sub-PM10 particulates, much higher overall volume of emissions, more Co, shorter engine life with earlier/higher combustion of lubrication oil causing more smoke, much more rapid exhaustion of a finite resource.

Huge areas of land and enormous distillation plants would be needed to produce enough fuel for thirsty spark ignition truck engines.......... you really cannot be serious, as somebody once said and I still hold that the dangers inherent with making and transporting alcohol are not worth the risk, just one bad accident could kill more people in one go than in years of use.

Whole life costs! You cannot just count "use" toward whether something is "good" or "bad" you have to count from making it to disposing of it as well. The ill effects of getting rid of an old one and making a new one can easily outweigh the ill effects of using one that is maybe not quite as "good" as it could be.

So diesel is now "poisonous" is it - just what is petrol then?
Scanner, I sincerely don't want to go on with this discussion with you and not because I finished my arguments.
Bye.
Alberto.
 

Offline scanner

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Of course you haven't finished with your arguments because you don't have a valid position to argue from. All you do is repeat your opinion of flawed and biased data. IF diesel was anywhere near as poisonous as you claim it would be banned just as tetra-ethyl lead was in petrol and benzene has partially been - 1% of petrol can still be a KNOWN (not suspected or just plain possible-maybe) carcinogen.
A move away from diesel as the MAIN motive fuel to petrol or even alcohol would result in a huge overall increase in pollutants especially CO2. Your "solution" would be totally unsustainable.

Until we can stop using the IC engine all together, we need to continue using the one which has the least OVERALL ill-effects and at present most sensible observers agree that is the diesel and that is why research into making it even cleaner is progressing so fast.

Please update your "studying and sampling" to drag yourself kicking and screaming into the 21st century - both diesel engines and diesel fuel have improved hugely in the last few years and I consider your views need to catch up.

Goodbye

Stefano
 

paul.fr

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Scanner, I sincerely don't want to go on with this discussion with you and not because I finished my arguments.
Bye.
Alberto.

No offence, but i have to say it's about time...


Paul
 

Offline ukmicky

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BY SCANNER Until we can stop using the IC engine all together, we need to continue using the one which has the least OVERALL ill-effects and at present most sensible observers agree that is the diesel and that is why research into making it even cleaner is progressing so fast
You are kidding of course, YOU CAN NOT BE SERIOUS ,you talk about people on this forum being blinkered in regards to their bias towards petrol and yet you are doing the same with you bias towards diesel.


I ASK EVERYONE TO DO A BASIC GOGGLE SEARCH ON "How toxic is diesel compared to petrol 2006 "
 
You will find that every study performed by every health organisation on the dangers of diesel pollution , even the world health organisation report that diesel pollution is many times more hazardous to life than petrol.Did you know that diesel is the number one air poluter in California even though it is nowhere near the number one fuel which is petrol.
The World Health Organization has concluded that, globally,particulate matter causes 460,000 premature deaths each year. Diesel engines generate primary particulate emissions – accounting for 20 percent of direct PM10emissions nationally. EPA has projected that by 2010, direct PM10emissions frommobile sources will be over 600,000 tons, with diesel engines contributing nearly 70percent.
____________________________________________________
THIS WEBSITE GIVES A GOOD BASIC RUNDOWN

For over ten years the U.S. Environmental Protection Agency(EPA) has worked to reduce the amount of emissions that die-sel trucks and buses are allowed to release, due to the threat posed to human health and the environment. Much less has been done to clean up diesel fuel and diesel engines than gaso-line alternatives. Diesel fuel not only contains a higher portion of dangerous substances compared to gasoline (as a result of less refining), but also the high-heat combustion in diesel engines allows a larger portion of these substances to form and be released. The high heat in diesel engines creates NOx. NOx reacts with sunlight and Volatile Organic Compounds (VOCs)to form smog, which triggers asthma. The Clean Air Network estimated that in 1997, smog triggered370,000 asthma attacks, and 9,600 emergency room visits in Pennsylvania. Fourteen Americans die every day from asthma. SO2 contributes to par-ticulate matter (soot) and when inhaled, particles of soot get lodged deep in the lungs causing in-fection, and potentially cancer and premature death. CO de-prives the heart, brain, lungs, and other tissues of oxygen.Diesel exhaust contains more than 40 toxic substances, many more than are found in gasoline. The U.S. EPA stated that die-sel exhaust is a ‘likely human carcinogen’, or cancer-causing agent. Studies in California suggest that over 70% of all cancers attributed to air pollution are caused by diesel exhaust.Carcinogens in diesel exhaust include arsenic and benzene. Other toxics include formaldehyde, cyanide, dioxin, ammonia,and 1-3 butadiene which, can cause long-term health problems such as lung, kidney,and nervous system damage, and short-term effects such as skin and eye irritation,and aggravated respiratory problems
http://www.cleanair.org/Air/diesel_factsheet1_danger.pdf
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Diesel fuel contains more energy per litre than petrol and coupled with the fact that diesel engines are more efficient than petrol engines, diesel cars are more efficient to run. Diesel fuel contains no lead and emissions of the regulated pollutants (carbon monoxide, hydrocarbons and nitrogen oxides) are lower than those from petrol cars without a catalyst. However, when compared to petrol cars with a catalyst, diesels have higher emissions of nitrogen oxides and much higher emissions of particulate matter.
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http://www.ace.mmu.ac.uk/eae/Air_Quality/Older/Cars.html
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While diesel vehicles make up only about 10% of vehicles on the road, they are responsible for belching out 80% of traffic emission problems.
http://www.medicalobserver.com.au/displayarticle/index.asp?articleID=7332&templateID=105&sl=1
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Swedish consultancy agency Ecotraffic report ,showed  that the cancer potency of diesel exhaust is more than twice that of petrol cars. If only particulate emissions are considered, the carcinogenic effect of one new diesel car is equivalent to 24 new petrol cars and 84 new CNG cars on the road.
According to a study conducted by the German Federal Environment Agency, diesel is "several dozen" times more cancer-causing than petrol.
http://www.cseindia.org/dte-supplement/air20040331/toxic_risk.htm

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There is no real debate that breathing diesel fumes is hazardous to the publics health. Compared to auto emissions, which are bad enough, diesel fumes are especially noxious
.

The World Health Organization reports that three million people now die each year from the effects of air pollution. This is three times the number who die each year in auto accidents.
A 1999 study by Southern California's South Coast Air Quality Management District (SCAQMD) found that diesel soot accounts for 71 percent of the cancer risk from all toxic air contaminants.
Only 2 percent of all vehicles on the road in the U.S. run on diesel, yet diesels account for 27 percent of the smog-forming pollution and 66 percent of the soot produced by all of the nation's motor vehicles.
Over 30 human epidemiological studies have found a link between diesel exhaust and lung cancer.http://www.aacog.com/schoolbus/Parents/Parents.asp


Quote
Diesel engines emit huge quantities of particulate matter, nitrogen oxides and more than 40 toxic compounds that have been linked to cancer and other serious health impacts. Particulate matter is associated with increased asthma emergencies, bronchitis, various cardiopulmonary ailments, cancer, heart disease and premature death. Nitrogen oxides contribute to ground-level ozone formation, smog, and nutrient pollution in waterways. Up to half of the particulate matter measured in the nation’s largest cities comes from diesel tailpipes. Roughly one-quarter of the nation’s nitrogen oxides come from diesel engines. Diesel exhaust (or diesel particulate) has been found to be carcinogenic by the U.S. Environmental Protection Agency, the California Air Resources Board, the World Health Organization and other public health agencies around the world.
http://www.nrdc.org/air/transportation/trk0600.asp

______________________________________________________
http://72.32.110.154/media/pressReleases/001120a.asp

http://www.arb.ca.gov/research/diesel/dpm_draft_3-01-06.pdf


http://www.cseindia.org/aboutus/press_releases/press_20040728.htm

I could go on and on but every study or report from every major heath organisation basically concludes that petrol burning cars pollute less and the pollution that they do give out is less hazardous to our health than diesel, so i may as well leave it as that apart from.

Personally over the years i have driven a hundred or so different diesel powerered vehicles and have driven many thousands of miles in them through my work , but give me the choice and i would have jumped into a petrol car or van everytime because Ive prefer the refinement and responsiveness of the petrol . Also when it comes to health and the dangers of different types of fuels i prefer to listen to the experts like  the U.S. Environmental Protection Agency for example.

.
« Last Edit: 22/02/2007 03:42:59 by ukmicky »
 

Offline Karen W.

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I live in California and Let me tell you!! LA has tons of diesel cars etc.. Not to mention High numbers of Big Rigs delivering through there daily... Me Husband Having been one !!! There are plenty of disel powered vehicles there despite the veiw taken earlier on there not being accessible or something in LA with their smog factors.. BUNK!!! I am no expert, but LA IS FULL of diesels all varieties!!!

  Michael YOU ROCK!! LOL
 

Offline scanner

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UKmicky I don't deny diesel pollutes or that petrol pollutes or that they pollute differently.

But US research does not apply in the EU as many factors are different not least the quality of fuel. US diesel is dirty unrefined stuff and is not comparable to EU standard fuel in any way - especially bio-diesel and modern high-tech diesels like V-Power and Ultimate. Once again you are only referring to particulates from diesel - PM10s - petrol produces PM2.5s and PM5s why do you ignore these and their ill effects?
NOX yes diesel produces NOX but in very low concentrations and less now than ever dues to ever better EGR systems. But over all diesel produces less total emissions as it's greater efficiency burns less fuel in the first place.

If things are really so bad why is diesel overhaulling petrol hand over fist as the major motive fuel in the EU?

So
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diesel exhaust is a ‘likely human carcinogen’
is it? Just what is the 1% benzene in petrol then?
I am puzzled by the reference to benzene in diesel exhaust, where would that come from there is no benzene in diesel. It is added to petrol to improve octane ratings - diesel doesn't have or need an octane rating and the very reason it is added to petrol is why it WOULDN'T be added to diesel.

All your quotes relate to the USA and as such are a red herring as those conditions do not translate to the EU as very different circumstances apply and have done for a long time. In any case the EPA is well known for inflating it's case against diesel and totally ignoring the ill-effects of petrol.


OK so you prefer petrol engines, so do such paragons of logical thought as Jeremy Clarkson and Tiff Needell. I would be interested to know exactly which models of diesel car you have driven and how recently that was and when you last drove a petrol van as they are now an endangered species.




Ohh and Karen could you let me know EXACTLY what fraction of 1% of the CARS (not trucks, pick-ups or RVs)in LA are diesel powered? UKmicky states that less than 2% of ALL VEHICLES in the USA are diesel powered, so if you take out all the trucks pick-ups and RVs that cannot leave many % to be cars.

Perhaps the California Dept of Transportation could let you have the figure. I don't think it will take that long to add up.

If it is more than I think, I must say how impressed I am with the good sense of some of your countrypersons.

 

Offline Morepower

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Sorry to restart an old thread. I read it all with great interest and I can see both sides of the argument. Neither fuel is healthy and I use both fuels. Petrol in my Motorcycle and Diesel in my car. Now as far as I was taught whilst I worked in the Coal mines dust and particulates were a risk to health and I know people who have died from mining related illnesses. We were always told that if you can see the dust it would be filtered out by our bodies defences and the smaller non visible particles were the highest risk. So when we are looking at particulate emissions surely we need to look at total volume regardless of size and be aware that the smaller particulates have a higher health risk. Again we also need to look at not only emissions per liter of fuel used but also per mile or kilometer. If a diesel can go 30% further per liter than petrol we need to look at it over the amount of fuel used and the distance involved. OK cities are hard work due to volume of traffic but we need to look at ways of reducing the number of vehicles in our cities with options based round less localised pollution. I know electric trams and other public transport has emissions which are away from the urban population but as with LA in the US this lack of ventilation or flow of air over the traffic jams will harm more people who come into contact with it.Electric city transport systems powered by rural wind farms are as clean as we can get at the moment. But I digress.
The energy in diesel is potentially greater than in Petrol and in recent months diesel engined cars have not only won world endurance races but European touring car races and these cars are based on the ones we drive. OK they may be tuned engines but they are all 2 litre and turbo charged, which is as close as any race car will get to being similar to ones we drive.

newbielink:http://www.fiawtcc.com/fiawtcc/season/2008/sport_sto1565962.shtml [nonactive]

As you can see if you look at the link these diesel cars are beating petrol engined ones so power is not too much of a problem with good engine management as these engines are limited to 4100 RPM and have limited boost and fuel pressure applied to them. Now I think unfortunately Diesel will be the fuel we look to more in the future and the US market has not got the volume of diesel vehicles partly due to the poor agricultural quality fuel they use, which almost all the more efficient European and Japanese vehicles now cannot use.There are no top spec European diesel engined cars in the US due to the poor quality fuel. Also as a small by product of US fuel pumps which use one fuel gun for all the fuels which causes the first part of any change in fuel required to take the residue of the other fuel in the lines. Mixing petrol with diesel or vise versa is not good. I was also confused with the comment about Benzine in diesel emissions as Benzine is there to increase octane rating and diesel uses Cetane numbers for its rating and benzine has a negative effect on diesels cetane ratings. I do not argue either fuel is unhealthy but long term bio fuels will be more common and bio diesel in modern engines will become cleaner and exhaust gas recycling to clean up the harmful particulates will become more effective as will the use of catalysts which may not be good for the environment when we make them but will cut down on poisoning due to the use of internal combustion engines.

I do not want to get too wrapped up in the whole argument of either fuel as I have not got the experience of a petrochemical scientist or work in the industry. But from a simplistic point of view if we use less fuel per mile and can use technology to reduce emissions of any type I am in favour of that. Petrol has a limited life and E85 fuels are not an answer with older vehicles as they take a lot to convert over as they use more fuel by volume then petrol alone and fuel injected engines in some cases cannot be adjusted to flow enough E85 and it has a lower energy output per litre to work fully where more modern Diesel fuels will work with older diesel vehicles as the basic principle has not changed and the energy per litre will stay fairly constant.   
 

Offline Morepower

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Deisel is like kerosene and it is not as explosive as gas, so it doesn't have as much energy potential as petrol, whereas the gas has a higher energy potential.


Diesel has a higher energy content than Petrol.
1 gallon of gasoline = 124,000 Btu

1 gallon of heating oil or diesel fuel = 139,000 Btu

If you have to make a point please get it right and the above quote doesn't allow for the newer European low sulphur fuels which now have helped evolve diesels in Europe so far that they now cannot be sold in the USA due to the poor quality fuel sold in much of the USA. It is almost the same grade as used in farm vehicles (called Red Diesel in the UK) and the stuff used in 3rd world countries. 
 

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