Klean Diesel Kaput

no offense to vw/diesel lovers (i drove one for 5 years) but you're comparing apples and oranges. if you don't want to compare mpg and you can't offer details of a diesel hybrid technology, and you throw around a lot of numbers and terms no one understands and you admit a diesel is not as clean as gas, then, what's the point?!?

 

The point is that a fair comparison between engines is BSFC. It doesnt matter what size or what power it makes, BSFC levels the playing ground. My so called fuel guzzling diesel truck is more efficient than a prius motor.

Now as far as mpgs, comparing a hybrid gas to a non hybrid diesel is apples to oranges. As of now we have no accurate mainstream way to compare them.

But it is safe to say that there is a very good chance a diesel hybrid will surpass the Prius in fuel economy.

On another note I just caught wind that the 2010 TDIs do not need SCR as they are already clean enough.

Just like the Prius owners are flaming the TDI guys right now, they will be in the same position as us when Toyota releases a diesel.

 

a) who cares about comparing engines? you hardly read anything on this site about the prius engine, it's all about hsd!

2) it is not safe to say it unless you have done it.

B) clean enough is not as clean as aprius.

3)not sure what you mean by prius owners flaming you. is that an insult?

 

1. Comparing engines is a level playing field as I haver mentioned. If you do not want to use the fair engine comparision due to the Prius engines low number that is your choice. Put the HSD behind a TDI and see what it gets for mpg, i bet it would do better.

2. Whats not safe to say unless Ive done it

Clean enough is not as clean as a prius. Again apples to oranges here. the Prius does not constantly run the engine, thus the emissions are much lower. The 2010 Diesel emissions standards have been said by some to be cleaner than the air some people breath.

If you bought your Prius for emissions reasons, fine you win.

3. The flaming part was to an earlier post that was not yours.


Again you are entitled to your opinion. And as always I am open to an educated, adult debate.

 

Before this thread degenerates into a flame war, let me state that I really like diesel engines. I'm not talking about emissions, fuel economy, or anything like that. The gearhead in me just thinks that they are cool. I love the basic simplicity; it's really quite elegant.

I have a big hulking single cylinder marine diesel in my sailboat, and it's an excellent engine for that application. Likewise I drove a really sweet Toyota turbo diesel a decade ago when I was in Paris. I would have considered buying one of those if they had been available in the United States.

Not all of us hate diesels, although almost everyone on this site really likes Prius.

Tom

 

I have never had a client mothball a CHP, I would seriously question the engineering behind a failed CHP installation

Whether chemical plant, thermal enhancement for oil extraction, chiller absorption preheat, etc, CHP wins far more often than it loses

Where CHP does poorly is if base rate is quite low, with few peak penalties, and no utility incentives. For example, Manitoba Hydro has about the lowest power rates in North America. They caution against co-gen

Connecting Customer Owned Generation

However, they do offer good incentives for geothermal exchange

For your business — Commercial Earth Power Program

so an honest assessment of incentives, costs, and ROI are required. I personally have refused projects that are dubious at best, based more on wishful thinking that solid engineering

 

Only the old fashioned diesels are "simple." Modern electronically controlled diesel engines are quite complex

For example, old fashioned diesel engines were naturally immune to EMP effects. Folks think that ALL diesels have this "immunity." Nothing could be further from the truth

 

There are two sides to that story though. With the complexity of new diesels comes somewhat easier data aquisition about the engine. Which is also bad because it creates lazier mechanics.

The common rail injection system is also quite simple. There really is nothing to a CP3 pump versus an inline plunger pump. The injectors are more complex but I dont know of many people that even dare to rebuild their own.

To compare new diesels to old diesels I challenged a buddy of mine to a race. He was to remove, rebuild and install the 12valve cummins in his truck.

I was to do the same with my "sophisticated" Duramax.

we both had bent connecting rods at the time so it was the perfect time to do it. We didnt do it for anything other than a good joke for the most part.

In the end, i was about 2 hours quicker. But that really doesnt mean a whole lot. The point is that they are not that much more to work on, IMO.

now a ford powerstroke on the other hand is a different story.


And one other thing before DEF gets brought up as being expensive.

Many of you are familiar with AdBlue and its ridiculous cost. AdBlue is like the champagne of DEF. Its not better than generic DEF which runs about $5-7 per gallon at truck stops.

 

The 2.0 TDIs in the Jetta, Golf, and A3 have never needed SCR. The bigger ones do. I'd be curious to see how fuel economy would change if they decided to do SCR on the 2.0.

 

I think it would hurt their sales due to the common perception that SCR will make the vehicle more complex and cost more money as well as the added cost of DEF.

However you and me Im sure both agree that the benifits of SCR outweight the costs.

This is what Cummins is going for. " In cylinder" technologies to make a hotter more complete burn which in turn will increase NOX levels but with the SCR to pick up the slack, the NOX is not an issue.

The 6.7: cummins also does not need SCR. But from what I have gathered Cummins is working as hard as they can to either eliminate DPFs or make them better performers.

 

Well, "simplicity" in this context is lack of a powertrain control module, many sensors, electronics, and wiring harness. Unless there is a hidden manufacturing defect, those electronics are usually very reliable for the long haul

An example of a "simple" and easy to repair diesel is the old Lister. You can easily find working example of them in Africa and India, some of them 6 decades old and kept chugging along with routine maintenance and the occasional overhaul

The huge Prime Mover engines have had some form of per-cylinder control for awhile now. With per cylinder timing, injection, and valve control, the engine makers should be able to produce a motor with good power, good fuel economy, and low emissions

 

I own a diesel (Cummins) truck. The power, torque and fuel efficiency is impressive, especially on the highway where the rpm range is fairly constant. However, diesel engines are heavier than their gas "cousins"; they are noisy; and they do smell. Most are turbo-charged .... I do not know if that is a factor to consider. Plus, diesel fuel is more expensive than low-test gasoline, and not as readily available.

I too wonder about the repeated starting and stopping of a hybrid. The Cummins has two-12 volt batteries to provide the "cranking" power to start the engine .... I wonder if a Prius type CRT could handle the load??

I suspect that should VW develop a diesel hybrid, it would require much different technology from the Prius and Fusion hybrids. Maybe closer to the Honda system??

It will be interesting for sure.

 

Diesels are more thermally efficient due to their higher operating temperature. But where Durallymax wants to compare engine to engine, I want to compare car to car, because it's the car I utilize for transportation.

The Prius gains its efficiency and low emissions through a complex system, of which the Atkinson-cycle engine is only one component, but a component that is very well matched to the HSD system. It is not clear whether you could drop a "clean" diesel into an HSD car and have a functioning automobile.

I personally dislike diesels because of the smell, the noise, the particulates, and the vibration. I dislike gasoline engines for much the same set of reasons, but I see diesels as worse on all counts.

And finally, development of the HSD system required many years and a great deal of investment and is an engineering marvel. It is not known whether VW will be able to match Toyota's engineering feat by developing a hybrid system for diesel that is as elegant or works as well as Toyota's HSD.

I admire people who are burning used cooking oil for transportation because they are making use of a resource that was formerly dumped into landfills. More power to them! But I don't want a diesel. If I have to burn something for transportation I'd rather have a clean-burning Stirling-cycle engine. External-combustion engines have the potential to be much cleaner than internal combustion.

 

The new diesels are very quiet, im assuming you have an older dodge cummins (pre 2007). These were very loud.

i encourage you to go to a dealers lot and listen to a new duramax or powerstroke run. they are very quiet and IMO quieter than many older gas engines. Granted you wont find a new duramax on a lot because they are not being made right now.

The smell coming out of new diesels smells like glue to me. Older diesels were dirty.

Nearly every diesel over 50hp made these days has a turbo. It is crucial to its performance in both power, efficiency and emissions.

Also new diesels are much lighter. Using new technologies such as compacted graphite iron cylinder blocks, aluminum heads and lighter yet stronger internals, the weight has dropped significantly.

Bigger diesels take alot of CCAs to start. A Duramax uses two batteries totalling nearly 1600 amps. Smaller diesels still take more CCA than their gas counterparts but can do so with fewer amps.

 

Hi Bob, I do understand the basics of Atkinson cycle, that many hybrids use it, and why it works so well in a PSD hybrid. That's about the extent of my knowledge, but I imagine it's no worse than that of the typical Prius owner here. Ecomodder is not the best source for TDI information. You should check over at TDIClub if you're looking for something TDI related. I am sure that you would be able to acquire enough information there to produce the chart that you want.

Unfortunately, I don't think you'll find the operating line for a TDI automatic. However, here is one for the 1.9L engine with a manual transmission:



Hope that helps,

Mike

 

I do know how the atkinson cycle works, but it is still not as efficient.

The maps you show use different scales. I dont know what their Bar measurement is. Bar as many know is a pressure reading. Going off of the manifold pressure in a diesel is a good way to determine the load on the engine however that map goes to 20 bar which would be 290psi.

perhaps im just dumb, but maps with similar measurements or ones that could be converted would be a fair comparison.

Transmission does not affect engine BSFC. unless the BSFC maps you are showing do factor in the transmission.

Then again it is an unfair comparison, electric assist versus 100% engine.

 

1) comparing engines is not the title of the thread. "klean diesel kaput" vw says it's going to make hybrid gas/electric and pore ev, not hybrid diesel/electric.

2) it's not safe to say a hybrid diesel/electric would have better fuel economy if one has never been made. it might in theory, but if you can't build one for technical/marketable/economic reasons, theory is just that.

3) i purchased a prius for the environmental reasons first, to promote new technologies second and for fuel efficiency third.

4) if you want to argue engine vs engine efficiencies, you should start a thread about that. perhaps you may win that debate, if there is anyone to debate with.

 

Wait until you have about 50k miles on them! They do sound very quiet and smooth when new but start to rattle and clatter more as the mileage goes up (after about 50k). Yes I have experience of diesel cars (from europe) using the latest crd technology. I have driven them for the last 10 years. I'm not anti diesel but they do have downsides as I've previously indicated elsewhere.

Despite some downsides I do think they should be looked at in the USA as there are benefits too. Whether they will become overly complex and too expensve because of all the emission control equiptment is debatable.