why no prius diesel hybrid?!

I agree. And don't forget, runs on filtered fast food grease too!

 

Except for the weight and the noise, and the temperature requirements I think a hybrid diesel makes sense.

In '79 I bought a VW Rabbit Diesel 4 speed stick, waited in line to buy one because of the worse oil problem then (tripling of price, shortages, rationing, odd/even fill up days). My MPG was in the 45-55 range freeway and overall around 40. I got better than the EPA estimates!

VW did a stupid thing in 1980 when they started making them in the U.S. The quality went way down and ruined consumer satisfaction. My Wolfsberg edition was great, but my friends '80 was riddled with problems including vibrations so severe the steering wheel came off while I was driving his car on the freeway:faint:

I loved mine though and wish I still had it!

 

Nonsense, diesel fuel has a higher carbon content and therefore 30% higher energy content/gallon. It also ends to be more expensive in the US so the miles per dollar is the issue, not miles per gallon.

Not true, They emit more co2 per mile and more NOX. The Prius (and some other cars) have a PZEV rating. There is no diesel with this clean an exhaust.

True, but not in stop/start mode as in a full hybrid.

Again true but the more torque at low RPM is not required in a hybrid as the electric motors have tons of torque.

The best use of a diesel engine in a hybrid would be in a series hybrid (like the Volt) where the ICE just drives a generator so that the battery capacity is not the range limitation.

Jeffd

 

(2) Not true - currently there are no diesel cars sold in CA because they don't meet the emission standards. There will be MY 2009 cars sold but even then they are dirtier than the best gasoline cars, and there is controversy over the impact of the very fine particulates that they do produce but will be allowed.

(4) Not true - in general a diesel of the same technology level will generate less power and torque than an equivalent gasoline engine:

For example the figures for the 2006 VW Jetta are:

Gasoline(turbo charged): 200HP @ 5500RPM, 207ft-lb @ 1800RPM
Diesel (turbo-charged): 100HP @ 4000RPM, 177ft-lb @ 1800RPM

A gasoline engine can run faster and so its power peak will be at a higher speed. In part this is because the rotating parts of a diesel engine have to be made more stronger and heavier in a diesel engine. Often the peak torque of a diesel will be at a lower speed than a gasoline engine - this may give the impression of more torque as often a gasoline engine will tend to stall at low RPM (my BMW 328 was an example of this although a fine engine in all other respects).

Although I would like for someone to produce a diesel hybrid other items to consider are that diesel costs 10-20% more (in the US) and that the refinery can get up to twice as much gasoline from crude oil compared to diesel.

kevin

 

You are comparing apples to oranges - for the same size engine and similar technology a gasoline engine will produce more torque - you are comparing a naturally aspirated gasoline engine with a turbo-charged diesel. If you put a turbo-charger on the gasoline engine you could probably get more torque than the diesel.

A diesel engine limited in how much you fuel you can inject before smoke appears in the exhaust due to incomplete combustion (the smoke limit) - a gasoline engine can get to a stoichiometric mixture or richer without this happening.

These are also much larger engines than will be used in a hybrid Prius!

My example of a VW Jetta is much more appropriate.

kevin

 

All of your points are right on. However, there would be an obvious demand. The bigest issue would be the exhaust - scrubbers in the manifold?
The increased efficiency might offset the costs. But how would you constantly stop and start the glow plug based diesel thumper and how efficient would a tiny diesel (smaller than the Rabbit diesel) be mated with an electric motor?
Anyways, we need annual carbon taxes per vehicle to be paid with registration. i.e Charger SRT 8 = big tax, PZEV vehicle = small tax. Sorry that is a whole new thread.

 

One note... diesels have a narrower range of operational rpm compared to gas engines... it wouldn't work with the current MG1/MG2/ICE integrated CVT system. A hydrid diesel would probably need a separate transmission.

 

A diesel / electric combo (think locomtives) would give you instant torque and real good mileage. The emissions would have to meet the new standard coming out in 2010.

Also, how many of us would be willing to pay more for the diesel option as well as more $$$ / gallon of diesel?

Dbcassidy

 

Hi All,

Diesel engies cost allot to machine, due to the harder heavier metal they are made from.

The Prius can outdo even a Turbo Diesel in metro traffic. So, it seems its better to get that advantage first. This is where the majority of cars are used.

Diesel has poorer well-to-tank petroleum usage. It takes more petroleum per tank of Diesel. Toyota has said its a wells-to-wheels efficiency it was driving for. Diesel has better mileage, but worse miles per petroleum barrel. Modern Refining methods (catalysts) yield more gasoline. Jayman may comment on this - he is an expert - so wait for what he says on this.

DPF (Diesel Particulate Filters) are being retrofitted on even used diesel cars in Europe, and are required on new cars. Since the requirement of DPF's, the Ethiopian drought has dramatically abated. There is science to link the two. Large numbers of particles in the upper atmosphere tend to keep water alloft. Downwind from Europe is the NE portion of Africa.

Turbo's are a maintenance issue. They tend to loose the bearing between 70 and 100 K miles.

The Atkinson engine in combination with the HSD transmission, is nearly as efficient on the open road as a Turbo-Diesel. And more so at reduced speeds (50 to 55 mph) - Wayne's 71 mpg trip from Chicago to NYC.

 

The idea of running off a fuel not coming from the Middle-East is very attractive. I have some friends that modified their diesel engines to run off waste cooking oil. Biodiesel fuel can also be made out of organic waste, switchgrass, etc.

Anything that reduces our dependance on Middle-East oil is good.... less wars, less violence, etc.

In our city there is a company specializing in supplying filtered waste cooking oil. If I could have a hybrid diesel, I would definetly consider it. ecoauto - menu

Diesel - Wikipedia, the free encyclopedia

The link above shows some interesting information about diesel fuel... like I said earlier it can be made from biomass... It would be great to reduce our landfill mass and using the organic waste to produce synthetic diesel.

The section about Coal-To-Liquid is interesting too... producing clean synthetic diesel out of coal... North America has very large quantities of coal.

Another benefit (for us in cold climates) of diesel would be in passenger cabin heaters such as the Espar :

Espar - Automotive

The Espar would provide a heat source without requiring to turn the ICE on. The Espar might also be used to keep the catalytic converter warm to ensure proper anti-pollution efficiency and reduce the need to use the ICE to keep the catalytic converter warm.

I wonder however if diesel engines can sustain frequent start-stop cycles.

 

New Diesels

EDIT, just to summarize my overall opinion:
I think gas is best suited for hybrid, while small hi-tech standalone diesels may be the best bet for diesel's future. I guess Peugeot will have to prove me wrong...

In response to the turbo diesel/ turbo gas comparisons earlier, consider some of the newer diesels:

~3 yr/old engine just reaching US:
VW Tier 2 Bin 5 2.0L diesel: 140 hp / 230 lb.ft, 40 mpg mixed driving in 09 Jetta (The new EPA estimates for diesels are incorrect)

Newest:
BMW Tier 2 Bin 5 2.0L Turbo Diesel: 204 hp/ 295lb.ft

In BMW 123d: 45 mpg, 0-60 in 6.7 seconds, top speed 150 mph, CO2: 138 g/km

When I think that BMW can achieve 45 mpg from a 2.0l engine with 205hp/295lbft....I think why not give us the same technology without the super-car performance, say 100hp/150ftlb? Such an engine would not need to be more than 1.2-1.4litres. I drive an older diesel with those numbers and, trust me, they are more than enough to scoot a 3,000# car around.

I don't understand how you can argue a modern diesel is less efficient than a modern gasoline engine ...even taking into account the greater energy content of diesel.

I know of no gas engines matching this output while getting even close to the FE of this diesel.

Also regarding PM of diesels. All I want to say is there is very little research out there that compares diesel to gasoline. Diesels have gotten all the focus while DI gasoline engines are the elephant in the room as far as particulate emissions go. Gasoline engines' particulate matter is in general far smaller than diesel and some thus believe more dangerous to our health.

One other thing I wanted to add for now is that new diesels mark an end to WVO conversions, only the technology of the past will allow such a fuel. Even high blends of biodiesel may be out of the question in the near future. So a big upside for diesels, "reduce foreign oil dependency via alternative fuels," is no longer an upside. Oh well, biofuels have been a total flop anyway...

Will also add to address previous posts in which downsides of diesels were "weight" and "noise"
- The engine above is all aluminum, it is comparable to any turbo gasoline engine in weight.
- What noise? Test drive a 2009 Jetta TDI.

Also will address turbos as "maintenance issues" that "loose the bearing" every 70k - 100k: Just not true. Most turbochargers last the life of the car. I have 190,000 on mine if that counts for anything?


​

 

Hi ed...,

The ethanol thing has really killed the bio-gasoline oportunities. Specifically, bio-butanol. Until the ethanol thing runs its course, and a bunch of em go out of buisness, bio-gasoline does not have a chance. Unlike bio-diesel.

Besides, there are not enough deep-oil fryers in the US to provide enough diesel fuel for the diesel cars on the road in the US now. And in the winter, SVO fuel is unusable, as its gel point is what 30 something F, and Biodiesl like 15 F ? Modern high performance diesels cannot use SVO, due to the small orrifice size of the injectors (which is how they get the fine fuel particle size to promote complete combustion). The fuel needs to be lower viscosity than even heated SVO.

In warmer climates, Electric Cars are so much more effective than Diesels, anyway. And quicker than either gasoline or diesel cars.

Also, the BMW 123D is a $48,900 vehicle (24,480 UK Pounds , 1.9771 dollars per pound).

 

BMWBoard - BMW ChatRoom

Thanks donee, yes there is the issue of price. I believe I read somewhere that was why Toyota didn't use diesel, they feared the cost of both hybrid and diesel combined were too great for the market to bear.

 

I've been hoping for diesel hybrids since before the Prius was even around! Just a few notes to add to the thread here:

Glow plugs - this isn't really that big a deal - having the batteries we do on a Prius, we could fire up any kind of glow plug or spark needed to get the diesel combustion cycle going.

Diesel's power-band - also a trivial issue to address in a diesel hybrid - the HSD itself already transforms the impedance mismatch of the ICE and the MGs - moving from ICE to DICE - (D for diesel) just means different gear ratios and different programming.

Noise and clatter - that was 1979, not 2009 - after idle, you'd be hard pressed to tell a modern diesel from a gas car these days - the miracles of modern technology of course. Even at idle they're nowhere near as noisy or smelly as they used to be.

As for CO2 emissions, I think combining PZEV with blu tech or other filtering technolgy can only be a good thing. What's more is that a diesel is a simpler design than gas engine, having a much simpler electic component. People talk a lot about how complex the Prius' HSD is, but I think that it's the simplicity of it that makes it so amazing. Just think about the planetary gears in it compared to an old-school gas-pot with it's torque converter and the TWO planetary gearsets in the transmission - and that's all AFTER the ICE...
Then there's the versatility of fuels that comes along with the basic simlicity of a diesel design - also a great thing, considering biofuels, coal-based diesel - and perhaps as yet undiscovered alternatives.....

I'm just surprised to see so many people being so pessimistic about potentially great improvements in technology. Wasn't it optimism and proactivism that got you into a prius in the first place?

Anyway, just my .00002 space-bucks...
Cheers!
Dave

 

I don't see much unjustified pessimism in this thread. I see a discussion on the pros and cons of a potential diesel hybrid.

I'm just surprised you would like the discussion to include only positive input.

No, it was judgement. Being able to weigh the pros and cons and then make a sound decision based on goals/criterias to meet.

 

Well, there were concepts and cost US tax payer's $1.2 billion but they never made into mass production.

GM Unveils Concept Car That Gets 80 Miles A Gallon

 

Oh.

I wouldn't. I'm surprised at your surprise

I was commenting on earlier posts that seemed to make mountains out of molehills. Agrandizing technical issues as unsurmountable impediments is pessimistic, IMO.

OK, Maybe I had a little carry-over frustration from just having been over on the gminsidernew.com forum...

Dave

 

I suppose the next logical step I'd like to see would be a true deisel/petrol electric (think trains)
Unfortunately the battery technology isn't really up for it at the moment..

It'll come eventually.. think of a small 250cc deisel running on "fumes" providing the kW charge into a LiPo battery pack under the floor that provides the power to 4 individual drive motors with full regen on braking to get some power back to the batteries.

I guess the batteries wouldn't last long enough and would triple the cost of the car!
A lot of work would need to be done on motor generator and battery technology for this to come about.