Briefly discuss the difference between petrol and Diesel.?

Answer 1

Yahoo Answers does not exist to do your homework for you!
I realise this is fairly moot because people have already answered your question but here are a couple of tips for the future:

'Briefly discuss the difference between petrol and Diesel.?' is fairly obviously copied from what your teacher told you at school. Something that sounds less like homework (and hence will attract less of this type of criticism) would be 'What is the difference between petrol and diesel?' The change is quite small, but the second version will still attract answers. Then you could read the answers and do your own homework based on the information you glean from peoples answers. This is as opposed to what you will probably do which is copy the answers you receive directly into whatever it is you crazy kids do your homework in these days.

Answer 2

Steve is right in what he says. To add to that:

The gasoline range is boiled off (distilled) from crude oil first. Up to about C10 (hydrocarbons containing 10 carbon atoms like decane or dimethyl-octane. Between C10 and C22 or so, diesel is distilled off next. There is not a perfect separation between them, there is some overllap in the chemicals they contain.

Gasoline/Petrol is volatile. It has a significant vapor pressure (9 to 13 psi) in order to rapidly evaporate and pre-mix with air so that it will burn as a mixtures of gases.

Diesel is semi-volatile and is squirted into the engine as a liquid through a fine nozzle to spray a mist of it into the highly compressed and heated air. Air hot enough to auto-ignite the diesel oil.

Petrol has a lower density than diesel, about 15% lower.

In many locales, they are taxed differently depending on the political clot of truckers/railroads/airlines versus auto drivers.

It used to be that diesel was somewhat of a waste product because more gasoline was needed and therefore diesel was much cheaper. But 1) they can now do more chemistry to shift the cut between the two, 2) some autos have gotten more efficient while 3) over-the-road trucking has increased with Wal-Mart style just-in-time delivery. So in most of the USA, gasoline and diesel are priced similiarly.

Answer 3

do not initiate the motorized vehicle as there a diesel gas pump is finely machined and petrol does no longer have the lubricating traits. the standard enormous difference between petrol and diesel is the burn fee a petroleum engine makes use of a spark for ignition because the gas is quite volatile yet a diesel engine has a more desirable compression ratio and makes use of the bicycle pump on the accurate of the thumb theory. by doing this it heats the combustion chamber up too about six hundred tiers centigrade and diesel will self ignite at four hundred. You spoil out with operating a leaner mix with a diesel because the chemically astounding (stoichiometric) gas ratio for a petroleum is 14.7:a million and its 100:a million for a diesel

Answer 4

Petrol is a British word for the American "gasoline" (which I assume you knew because you used it).

Gasoline is a light ends hydrocarbon, about 8 carbons being the typical molecule.

Diesel is a heavier hydrocarbon, with 10-20 carbons being a typical molecule.

Ideal gasoline will not combust through compression heating but only with a spark (it is not "self-igniting", or has a high octane rating) while an ideal diesel will combust through compression heating (it is "self-igniting" or has a high cetane rating).

A diesel engine can experience greater compression in the cylinder, allowing a greater peak temperature and therefore higher energy efficiency (42% thermal efficiency is typical for a modern diesel), while a gasoline engine is limited in maximum compression and therefore has a lower thermal efficiency (20-25% is typical for a modern gasoline engine).

There are some technologies - like variable valve timing and direct injection for gasoline engines - that are going to close these gaps somewhat in the near future.