Gas, Hybrids and Diesel

[bertusgeert 1]

TO someone who knows...So why does Americans use so few Diesel engines? With the rising gas prices and the efficiency of diesel, don't you think that people would rather buy diesel cars than hybrids? (counting out the image factor)

What is the percentage of diesel users in europe? Why does the American cars not follow the pattern?

ANd lastly, one of my friends arguments was that diesel is much more poluting. Is that true?

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As jy dom is moet jy bloei!

[wmw999 2,123]

As an American (does that make me an expert? You have to find a gas station that sells diesel (and there aren't as many). You have to find a mechanic that works on diesels (and there aren't as many). The selection is smaller (and, after all, it's all about the largest possible selection).
Most people have seen black smoke coming out the tailpipe of a diesel, or smelled diesel exhaust coming from a truck; the perception is that they are more polluting on account of that.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[craichead 0]

There was a really interesting story on NPR yesterday about a guy using bio-diesel fuel that he makes himself...he said that the exhaust often smells like takeout/fast food, and he would joke about how many cars would pull off at the nearest McDonald's exit if they were following him.

http://www.npr.org/templates/story/story.php?storyId=4722639

Morning Edition, June 29, 2005 · Mike Pelly, owner of Olympia Green Fuels, uses bio-diesel fuel to power his two cars. He makes the mixture from used vegetable oil discarded by Chinese restaurants and fast-food joints. Pelly tells Steve Inskeep how it works.

_Pm

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"Scared of love, love and aeroplanes...falling out, I said takes no brains." -- Andy Partridge (XTC)

[wmw999 2,123]

Yep. I've been looking into it too, for whenever I replace my current car (which was pissing me off some, but I've started riding the bike more). There's a local co-op that I could deal with if I didn't want to do all the mixing myself.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[RevJim 0]

It balances out up here. thanks to the tax gods, the price of diesel around me is from 25 to 30 cents per gallon HIGHER than unleaded. So, if you get 30+mpg with gas, and 40 with diesel, is there really a difference? Well, yea, I guess, since every diesel car I've seen also costs more to buy than the gas counterpart.

It's your life, live it!
Karma
RB#684 "Corcho", ASK#60, Muff#3520, NCB#398, NHDZ#4, C-33989, DG#1

[billvon 2,400]

>So why does Americans use so few Diesel engines?

Primarily because gas has been so cheap (and still is so cheap compared to Europe.)

>lastly, one of my friends arguments was that diesel is much
> more poluting. Is that true?

Yes. Even the cleanest modern diesel is many times dirtier than something like a Prius. On the plus side, recent advances may be able to make diesels as clean as, say, your average two year gas car. But the technology is complex and sometimes annoying - one system requires you to fill up with urea every 15,000 miles.

[tso-d_chris 0]

Air Jose in Deland uses used cooking oil from a local Chinese restaurant in his diesel Mercedes.

When Rudolph Diesel introduced his famous engine at the 1900(?) World's Fair, he used corn oil for fuel.

For Great Deals on Gear

[SpeedRacer 1]

biodiesel is supposed to be cleaner.

NOt an engineer but: I've heard the only problem is NO (nitrous oxide) emissions, but those can be reduced by adjusting the engine timing

Problems with biodiesel: 1) can erode certain types of gaskets, but those can be replaced with polymers that don't erode.
2) It coagulates at cold temperatures. This is a prob. with petro-diesel as well, which is why truck drivers will leave their trucks idling on cold winter nights. But the problem is worse with biodiesel. But they have heat blocks for the fuel lines to prevent that.


I've also heard about people using 10% biodiesel in home heating oil.

Speed Racer
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[RMURRAY 1]

You will find a diesel in your DZ Cessna some day. Here is what I'd like to see in our U206. 350HP V8 turbo diesel, runs on JET A (same as a turbine)

http://www.centurion-engines.com/c40/c40_start.htm

[mx757 4]

Wendy
I never have problen finding diesel. on my 2005 VW TDI all you need to do is change oil every 10,000 miles and fuel filter every 20,000 (very important in a deisel) and replace timing belt at 80,000 VW TDI take over 60,000 miles just to "break in" they'll last 300 to 400, 000 miles easy. they do not emit any black diesel smoke / soot at all. they are very quite (for a diesel) I get arounf 42 mpg mix city / highway driving. 48 on highway. and I drive it hard / fast. it would do much better if I didn't do jack rabbit starts and drive 80 mph.. you'd be surprised at the torque of these little motors (1.9L) 100 horsepower / 177 ft/lbs tourqe.

[Elisha 1]

100 HP is hella weak.

[tsisson 0]

It's not about the HP...it's about the torque.

[Kris 0]

Quote

It's not about the HP...it's about the torque.

True dat. At 177 ft pounds of torque, that light 100HP car is going to move quite nicely.

Sky, Muff Bro, Rodriguez Bro, and
Bastion of Purity and Innocence!™

[Elisha 1]

...unless you put any sort of weight in that car.

[Kris 0]

Quote

...unless you put any sort of weight in that car.

You may want to do some reading...

What's the difference between horsepower and torque?

Sky, Muff Bro, Rodriguez Bro, and
Bastion of Purity and Innocence!™

[mx757 4]

Quote

100 HP is hella weak.

you'd be sureprised! 100 hp / 1.9l 4 cylinder with 177 ft/lbs torque... it's the torque make up for it.. go test drive one even better test drive the 2.0L 4 cylinder 134 hp / 267 ft/torque Passat!

[sundevil777 93]

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TDI take over 60,000 miles just to "break in" they'll last 300 to 400, 000 miles easy. they do not emit any black diesel smoke / soot at all.

From experience, there is at least one of those cars that does indeed belch out soot.

I think diesels should be required to have the exhaust pipe right on top of the hood.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[fueler 0]

Quote

biodiesel is supposed to be cleaner.

NOt an engineer but: I've heard the only problem is NO (nitrous oxide) emissions, but those can be reduced by adjusting the engine timing

.

negative ghostrider. its NoX(or NOx) oxides of nitrogen. caused ultimately by high cylinder pressures in a diesel. gas motors produce them also, but in much smaller amounts.

And no, you dont reduce them in a diesel with timing. the only thing to time is the injection of fuel. in a gas motor you can reduce cylinder pressures by retarding the ignition timing...but now you are spewing unburnt fuel out the exhaust port....sort of counter productive. im drunk and now im rambling. get some! i drive a big, overfueled, black smoke making diesel truck and like it.

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what!?

[Elisha 1]

Quote

Quote

...unless you put any sort of WEIGHT in that car.

You may want to do some reading...

What's the difference between horsepower and torque?

I consulted a source BEFORE I posted this. I stand by my statement.

[fueler 0]

you put any weight in a 1.9 litre anything and its going to suck donkey balls. the diesel will just suck less donkey balls.

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what!?

[RMURRAY 1]

Quote

you put any weight in a 1.9 litre anything and its going to suck donkey balls. the diesel will just suck less donkey balls.

I wish I could buy a Ford Focus with the 1.4 litre turbo diesel they sell in Europe but with this attitude (above) no wonder they are not for sale here. The smart car is for sale here in Canada and it uses a 0.8 litre turbo diesel but is a little small (just for commuting) and expensive...

[Elisha 1]

Check the manual of my car last night.

I have a 2.3L 4 cyl/162HP @ 194 ft/lbs of torque, so yours is definitely hella weak. Of course, you get almost twice the mileage, but that's besides the point.

[billvon 2,400]

>negative ghostrider. its NoX(or NOx) oxides of nitrogen. caused
>ultimately by high cylinder pressures in a diesel. gas motors produce
>them also, but in much smaller amounts.

>And no, you dont reduce them in a diesel with timing. the only thing
> to time is the injection of fuel.

Not really. The basic underlying problems are temperature and stochiometric combustion. In a gas powered car, a computer controls the amount of gas in the mix so that ignition is 'perfect' - it uses up all the available oxygen rapidly. No oxygen, no NOx (which is oxygen + nitrogen.) NOx can form under conditions of high temperature only when excess oxygen is present.

Two reasons diesels are so efficient is that 1) they have no throttle plate so no pumping loss and 2) they are inherently lean burn engines. The only time a diesel is using all the oxygen available is at WOT (wide open throttle, a misleading term when applied to diesels) - and most diesels are actually designed to give you a little _too_much_ fuel at WOT, because the extra fuel helps cool the engine. It also causes soot and fine particles from unburned fuel. But during normal low power operation, there's very little fuel and a lot of air, so the burn happens at very lean mixtures and at high temperatures from their high compression ratios. Hence the NOx problem.

There are a lot of ways to solve this. You can use a regular catalytic converter and inject urea. That's an ugly, inelegant solution. The most promising method I've seen is a dual catalytic converter/NOx trap with a fuel reformer to produce the scrubber gases, but it's expensive. I have a design that changes the control law on the engine to force stochimetric operation to scrub the the traps periodically, but I have no idea how I would prove it out. It would also make the engine sound funny.