what makes diesel fuel different than other fuel? (1 Viewer)

[LDfan]

I've always wondered about this but never knew the answer. Is there something special about diesel fuel and why do big trucks and other vehicles have to use it?

Thanks
Jeff

 

[Dennis Nicholls]

Well it has very LOW octane because you want the engine to ping - that's how diesels work. I'm not exactly sure what you are looking for in an answer.

 

[Lew Crippen]

Is there something special about diesel fuel and why do big trucks and other vehicles have to use it?

I’m not sure what you are looking for either. But, the reason that any vehicle uses diesel fuel, is because it has a diesel engine. It just turns out that big trucks have diesel engines, as do most heavy equipment. Some cars (Mercedes had diesel models since at least the 50s) also have diesel engines and require diesel fuel.

One reason that trucks and heavy equipment tend to have diesel engines and cars do not, is that while diesels have a lot of torque, they tend to not be so responsive as gasoline engines (a feature that many drivers really like—just tromp on the accelerator and off you go).

Diesel fuel for diesel engines and gasoline for gasoline engines.

 

[DustinLC]

Well, it just happened that we in the US decided to use regular gasoline instead of diesel in regular cars and it just pick up that way.

There's no reason why all cars can't be made to run on diesel. That's probably the way it should have started.

It's kind of like why we have VHS and not beta.

 

[Brandon_T]

I saw that Chrysler is coming out with a whole Jeep line, including the Liberty, that will be diesel in the next year or two.

Brandon

 

[ken thompson]

Diesel is actually an oil very similar to kerosene. Gas stations actually take the kerosene they have remaining after the cold season and dump it into the diesel tanks. I believe the low octane is needed because the combustion that occurs in a diesel engine is derived purely from compressions as there is no ignitions system or spark of any kind.

 

[Mark Sherman]

I tell you the best for a car is having the word diesel on the back, no one will steal it, Even better then LO-JACK

 

[Seth--L]

checkout:

http://www.reevesjournal.com/CDA/Art...,92450,00.html

 

[Dennis Nicholls]

There's no reason why all cars can't be made to run on diesel. That's probably the way it should have started.

It's kind of like why we have VHS and not beta.

Actually this isn't true. Back in the 1960's, people thought that diesel was "greener" than gas because it had lower CO and hydrocarbons than gas engines of that time . They didn't pay attention to NOx and particulates. Nowadays gas engines have no higher CO or hydrocarbons than the diesels, and have [rant]dramatically lower[/rant] levels of NOx (cause of acid rain) and particulants (cause of many health problems) than the diesels.

So by today's environmental standards, diesel is so much worse than gas that it really should be banned for passenger autos.

 

[Philip_G]

Ken pretty well nailed it. there is no ignition really, the glow plugs warm up and get the engine going, after that it ignites from the compression. As I understand it diesel is less refined and should be cheaper to refine, but around here costs a bit more :frowning:

they do kind of suck in the extreme cold. VW sells a pretty cool turbo diesel in their line of cars (beetle, golf, jetta) that gets nearly 50mpg.

 

[Michael Varacin]

Diesels are also way more efficient then gasoline engines. A lot less energy is wasted in heat from a diesel.

However, alcohol is where it's at. But the petroleum companies have too much pull in congress to push alternative fuels along. We will be dependant upon gasoline until the oil wells run dry for no reason.

 

[Keith Mickunas]

diesel is so much worse than gas that it really should be banned for passenger autos.

I think this is completely false anymore when discussing modern passenger cars running diesel engines. I believe that over half of new cars in Europe are diesel now. If you are behind a VW TDi, the only way you'll know about it is by looking at the badge. If TDi's can be sold in California, do you really think their emissions are worse?

Also, if diesel was more popular the price would probably go down here.

Then there's biodiesel. Its made from farming byproducts and thus shouldn't have the harmful emissions. I believe it lowers the mileage of the car, but considering its not oil based it'd still be better for the environment.

Americans are still stuck on the idea that diesel cars are smelly and dirty. If we could eliminate that notion, diesel sales would take off here and the environment would be better off for it. Sometimes I wish I had bought a TDi instead of my VR6 Jetta. The fuel costs would be well less than half of what I'm paying now. Diesel here is no more expensive than the premium my engine requires, and I'd get better than double the gas mileage out of it.

 

[Rob Gillespie]

Diesel engine cars are very common over here. Every black taxi cab you see is a diesel and virtually all common cars come in a diesel varient.

Gas mileage is much better with diesel because the engines don't require as many revs. The fuel is a few pennies more expensive, but the cars are cheaper to run. They do tend to be a little more expensive to buy though and the engine blocks are heavier. 50-60mpg are not uncommon.

I've test driven the same model car with a 2.0litre petrol engine and 2.0litre turbo diesel. The petrol is more responsive and quicker away from the lights. The diesel, is slower away from the lights but once it gets going it'll keep up with the petrol quite easily. The 40-70mph acceleration of diesels is often superior to the equivalent petrol and you barely have to apply any extra revs going uphill.

 

[LDfan]

Wow, this has pretty much answered my question about diesel fuel and the engines that use it.


Jeff

 

[Philip_G]

Actually keith, you can tell a TDi by the black streak on the bumper above the exhaust (seriously, I've noticed it on the TDi beetles if they haven't been washed)

 

[Christ Reynolds]

the best tdi resource anywhere is at www.tdiclub.com

CJ

 

[Joe D]

Diesel engines cost more money to produce than gasoline engines because they need to be able to withstand the pressure that is needed to activate the fuel.

By 2007 in the United States the particles will be significantly reduced for diesel fuel. In Europe they have already cut the amount of particles that are in the fuel, so it's a matter of what the standard is for the fuel.

Diesel has 1.3 times as much energy per unit than gasoline, which is one reason why the engines get better gas mileage.

 

[Eric Kahn]

Alcohol is not a viable alternative to gas, it cost to much to produce, you will only get half the milage of gas (half as many BTU's per gallon as gas) You have to distill it which takes a huge amount of energy
biodiesel is a much better alternative due to skipping the distilling and fermenting steps

I run plain old petro diesel in my TDI, Biodiesel cost twice what the petro stuff runs

 

[MarkHastings]

How stuff Works:
If diesel engines are more efficient, why do most cars have gasoline engines?

Read bullets 1-8. Pretty interesting.

 

[Rob Gillespie]

I think some of their info is a little out of date.

Diesel fuel is less readily available than gasoline

I've never seen a petrol station here that didn't sell diesel.

btw - my car is petrol!