petrol vs. diesel

[tommy666]

what is the difference between petrol and diesel? which is better for the environment? which is a better fuel? where is petrol used and where is diesel used and why? if u can answer any of these questions, id be grateful. thanks

[KebabMeister]

Petrol and diesel are both oils but refined to different levels; petrol is more refined.

As for which is better for the environment, well, there's many different ways of looking at it. There's direct polution of gases emitted from the exhaust which happen with both, although all petrol cars have catalysts and some diesels (?) have them too. CO2 is the most bi-product although this can be absorbed by nature via photosynthesis although perhaps not at the levels of CO2 output. Diesels also kick out a lot of soot. However, a diesel vehicle can generally do more mileage therefore it's using less fuel than a petrol vehicle for the same journey.

Better fuel is really dependant on your requirements. If you want speed then petrol is generally better but if you want economy then diesel vehicles are better. I would say that diesel is better because you can also get performance diesels as well plus the combustion process is more efficient than petrol.

Why are they used? I think petrol was originally used because it could provide better performance in the early days of motor transportation. It's really only since the modern car use of the turbo charger has the diesel provided adequate performance and therefore made diesel vehicles more desirable (as well as fuel economy).

Diesel is really the fuel of the future. It's cheaper to produce, engines are arguably more reliable in many different ways, burning process very efficient and with better fuel economy it may reduce the rate of fossil fuel (oil) consumption.

Of course, these are my thoughts/interpretations on the subject :) I've probably missed many obvious things out but I'm sure someone else can fill in the gaps.

[theo_wyvern]

autogas (or other name) is best !

[qapmoc]

You guys have just got to get in the picture about this subject, it does not matter which fuel is better or worse - lets put it plainly ''we are running out of oil NOW''

Thats real oil/petrol/diesel etc... that you use to run real cars and grow real food.

If you don't all get clued up on this it is going to be a big shock when the truth finally gets to you, google PEAK OIL and read some, this year is probably the last year in the history of the world that oil will still be cheap and easily available.

[tommy666]

thanks kebab, ur answer helped a lot.qapmoc, i didnt ask that question. im fully aware that fossil fuels are running out. i asked which fuel is better, petrol or diesel, i didnt say "OMG FUEL RUNNING OUT WHAT DO I DO?!?!"

[tommy666]

and actually, reading your reply again qapmoc, if you look at this question from your point of view, it DOES matter which fuel is better. i asked which is better for the environment, and i was told diesel lasts longer and so using diesel instead of petrol can help slow down the process of using up all our fossil fuels. also, i was told diesel is less refined. refining oil is bound to use up some more of the earths resources, and so using diesel will also help save on our consumption of fossil fuels.

so there :P (you got outsmarted by a 15 year old :D)

[qapmoc]

Hi tommy666, Yes you are correct but in fact your comment ''OMG fuel running out what do I do'' is the thing you should be worried about, don't forget that oil is not just fuel it is food as well. Do you actually realise that by the time you are 18ish the world could already be in a critical situation, the reason I said it is because it seems that most people have no idea what might be just around the corner and anything which makes even one person sit up and take note is worth the effort, Sorry if I hijacked your question.

[tommy666]

hehe its ok, i jumped down your throat a bit, but i wasnt really annoyed. you did put in a good point, and it doesnt matter that you changed the subject cos kebabmeister already answered my question. thanks 2 every1 who posted

[Whickerman]

Here in Ireland, the difference is about 4cent a litre.

[boobesque]

stand back while i refute kebabs 'diesel is the fuel of the future'.
there is a new engine being developed called HCCI (homogeneous charge compression ignition) which takes the fuel injection of a diesel and combines it with the air mixing properties of a petrol engine and uses multiple ignition points to create a uniform burn of the fuel thus creating more efficiency and less pollution. there are problems at the moment such as it is only really efficient at certain levels (above 1/4 and below 3/4 tank) and will potentially be available within the next 5 years.
but wait. theres more
the engine is not specific about the fuel that it uses so diesel, petrol, ethenol bio-diesel all work but at the efficiency determined by the fuels properties. hydrogen is being investigated currently as a source of fuel for the HCCI which being able to burn at a wide range of temperatures allows for an almost pollutant free engine.

[KebabMeister]

boobesque, well, when that is actually available and as popular as diesel and petrol I'll change my mind :) The problem with designing new engines and fuel types is the shear cost of design, manufactur and logistical issues such as fuel stations.

Diesel has and will continue to be developed and hence why I said it's the fuel of the future. The problem is that both petrol and diesel have been around for a very long time so it's going to be difficult for anyother fuel type in get in on the action.

[boobesque]

by 2012 according to the kyoto protocol, developed countries must reduce emmisions caused by vehicle transport dramatically. without the use of new technology this will not be possible. i believe that the current allowance for NOX2 for example, which is created by diesel engines must be reduced from its current figure of 2.5g per km to 0.2g per km. there is no way that current diesel technology can accomplish this and new technology must be embraced in order to meet the commitments to our environment.

[KebabMeister]

Perhaps there's no way of reducing Nitrates of Oxygen via catalysts (which petrol engines also produce but the catalyst burns off 98% of it) but they'll have to incorporate some form of exhaust gas recirculation valve to burn off excess pollutant before going into a newer style catalyst. The technology exists for this but I don't think many manufacturers are using it (Honda used it on their larger petrol engines but I don't know if they're still using it). Since the infrastructure, and engines etc., already exist for diesels they may find it easier to produce something that they can attach to their engines. It's far cheaper then designing, manufacturing, marketing and support a new engine.

As for the Kyoto agreement, this will probably apply to new vehicles and I can't honestly see the USA abiding by it because they're blatantly breaking it already and are among the worst polluters.

Anyway, we'll have to wait and see what happens. It's purely speculative what will happen.

[qapmoc]

Don't put too much faith in hydrogen as an alternative fuel, one of the problem's is that it takes more energy to produce than you get back from actually using it. see here for some info on that subject.

[rachaelhanna]

i personally use a diesel taxi every day and i think that they are grubby,smelly and sound really bad.
i would also like to say that once youve had one you have them all the dirt that lies on my skin is discusting i have at least two bathes a day.
also i always feel travel sick and want to puke all the time especially after i have driven in a diesel car.my dad runs one and i hate it they say that the diesel car is more efficient but i think it is a waste of money,i have spent around 3-4 hundred pounds in the last three years on diesel car taxies and i think that taxi firms should use petrol.