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Comments
Are you not aware of hybrid's ability to shut down the engine instead of idling? Your second statement suggests that you are aware. I'll leave it up to you to connect the dots.
"A diesel produces no HP when not needed."
Sure it does, during idling. It takes hp to overcome engine friction and minor pumping loss.
"What about starter motor stresses from frequent start stops ? "
You'll need to know how traditional gas engines start. Anemic starter motor spins the ICE up to 100 RPM before igniting with gasoline. But in Prius, the ICE is gently accelerated up to 1,000 RPM(it only take about 0.4 sec) before direct ignition. There are much less stress due to the combustion because the pistons are moving fast already.
"The penalties for keeping the engine idling and unloaded are MUCH less than doing the same with a gas engine, Atkinson cycle or otherwise."
Yea, that's why gas-electric hybrids stop the engine when idling. You are saying diesel engine would not benefit much from it as much as gas engine. Another reason why diesel electric makes less cost/benefit sense.
"You don't have to have a small/pathetic engine to complement the battery as the gas/electric hybrids."
Current gas-electric hybrids use a small engine because that's what it takes to do the job. Hybrids do not have to use a small engine. V6 hybrids are coming out soon. What's more important in a hybrid is an inexpensive and efficient ICE.
"Hybrid technology is still unproven in the real world. So, making a car so that it benefits from the battery pack, while not crippled when
a) battery loses charge
b) I can't afford the $XXXX to replace it when it fails".
Unproven? On the road for more than 7 years and someone used it as a taxi. Battery pack is made out of multiple modules. If one fails, the whole pack can still function in Prius. On top of that, a hybrid like HSD can generate electricity on the fly. The battery looses 20% of the original capacity after 10,000 recharge cycles. The battery is still functional after that and replacement is up to you. The same apply to the tires when you decide to replace them except tires don't last as long as HV battery.
Dennis
That is not true for a hybrid like HSD. Electric motors in EV are tuned differly from HV. First, 295 lbs-ft is from 0-1,200 RPM. That translates to 0-20 MPH and I know that's not high speed. The torque does not drop as fast as you think in HV electric motor. Prius has more passing power than 4 cylinder Camry because of the electric motor torque.
Lexus 400h FAQ - Is acceleration responsive or sluggish?
Actually, the Lexus hybrid's high-power motor provides maximum torque off the line, and the V6 engine offers plenty of power at medium and high speeds. In combination, the two will provide surprisingly responsive performance.
Dennis
One of the benefits of the TDI is that during the "no peddle demand" (drive by wire) say like on a long or extended downhill run, the computer presents a "no draw" condition.
Well obviously it begs the question: what is the speed with electric motor alone at 1200 rpm? Perhaps we could get this piece of technical info from the Prius enthusiasts!
I don't think that one has to go too far to realize that the ability of the gas motor to shut off during a portion of the % hours of operation is the main benefit to the gas/hybrid. So if it is good for that combination it should be just as good if not better for the diesel/hybrid combination. The places that come to mine is where there is a lot of slow moving bumper to bumper traffic like NYC Boston, WASH D.C. I think that one unintended consequence that when there is a larger majority of these types of vehicles that will probably cause even more congestion, due to the fact that most will feel they are not polluting like they used to so it is ok to sit more in bumper to bumper traffic!?
I mean how many of you would just buy the Prius with the anemic motor 1.5 that is paired to the hybrid? what would be the gas mileage of that same engine in the conditions described above?
I congratulate you on your Prius. I see quite a few of them around and think they are very beneficial.
as far as the report
http://www.epa.gov/otaq/models/analysis/biodsl/p02001.pdf is an EPA report titled "A Comprehensive Analysis of Biodiesel Impacts on Exhaust
NOx does go up, but all of the nasty emissions go down. NOx isn't even regulated as far as I know. Sure it's a concern, but not enough to warrant dropping clean biodiesel
Info from the classic Prius:
MG2 = 59.1 * MPH
When the main motor(MG2) is at 1,200 RPM, the car is at 20 MPH. The other MG1 can be anywhere from 10,000 RPM to -10,000 RPM(backward).
"So if it(turn off ICE) is good for that(gas-electric) combination it should be just as good if not better for the diesel/hybrid combination"
Sure it will be just as good in term of fuel saving. How about cost for benefit that gained? Diesel engine is pretty efficient during idling situations. Diesel engine is more expensive than gas engine which will make diesel-electric even more expensive.
Dennis
P.S: Please use Reply button so we know which message you are replying to.
The diesel engine is already pretty efficient. But there is still benefits to be obtained in using electric assist, particularly in stop/go traffic. Though the percent gain in MPG will not be as much as in gas/electric hybrids, the actual gain will be very similar.
Unproven? On the road for more than 7 years and someone used it as a taxi. Battery pack is made out of multiple modules. If one fails, the whole pack can still function in Prius. On top of that, a hybrid like HSD can generate electricity on the fly. The battery looses 20% of the original capacity after 10,000 recharge cycles. The battery is still functional after that and replacement is up to you. The same apply to the tires when you decide to replace them except tires don't last as long as HV battery
That does not constitute enough real world experience when it comes to automobiles. Please provide lifetime ownership information about hybrids. How long does it take for 10000 recharge cycles. What about partial recharge cycles. And what happens after 10000 recharge cycles. What's the real world cost per mile of driving a hybrid, compared to a similar gas car / diesel car.
Not only is it regulated, it is the most important factor!
NOx contributes directly to smog. And because diesel is so much higher in NOx (and particulate) emissions, the EPA restricts & limits sales.
CO & HC are also nasty, but not as nasty as NOx.
JOHN
I did a crude calculation awhile back. It came to 13.5 years of average driving.
> What's the real world cost per mile...
Claims have been made that diesel is "well proven" now. That should mean that there are very solid cost figures supporting that. What are they?
Make sure to mention the most important factor: the amortization schedule.
JOHN
Nevertheless - your point is valid on the hybrid technology.
The circuit breaker cut off electricity from the battery even before the airbags are deployed. Prius battery pack is 201 Volts. For reference, AC outlets in our home are 120 Volts.
Dennis
Dennis
Yes guys, I have also asked this question some posts ago!! If one guy has an entire web site devoted to Prius's, surely the real world cost per mile of driving a hybrid should be an additional point and/ or benefit. The fact that you all have assiduously ignored this is most telling!
Why does that question keep getting ignored?
Without that vital information, I can't even attempt to provide an answer.
Other details would be nice too; otherwise, it's hard to be specific.
JOHN
How would the lack of following an established standard be helpful?
You'd have no basis of comparison whatsoever, just a vague number.
JOHN
It won't change the reality that smog pollution is caused by NOx emissions either.
Remember, 60 million new vehicles per year worldwide means every tiny bit of reduction makes a difference.
Also keep in mind that Toyota has stated (many times) that they plan to offer the hybrid option on *EVERY* passenger vehicle they make by 2010.
What have the diesel automakers stated they plan to deliver in terms of emission reduction? A promise to meet the SULEV rating would be great. After all, prototypes of cleansing hardware have been demonstrated.
JOHN
huh?? the last time I checked diesel exhaust is the one that is potentially hazardous to health. That means, living healthy (by not going diesel) and maintaining domestic oil industry are congruent goals. Not that I think maintaining domestic oil industry is an important priority, but you seemd to think "kissing import oil bye bye" was worth the health hazard of switching over to diesel for higher mileage. I'm not for diesel at all.
Look to 2005 Toureg TDI for your answer. It's the first TDI somewhat in the same vehicle class with TLC. Previous TDI's have to be compared to Corollas and Camrys, and come out looking very dirty indeed. Don't forget, meeting emission standard is a multi-year thing; many TDI's don't fare very well in the long run in terms of maintaining emission control (engine durability is a different issue).
Because they are in different class. All VW TDI are passenger cars. SUVs and trucks normally pollute more. Unless VW put their TDI 110hp engine in the SUV body, they can not selling it in CA, NY and other crowded states. Just an explanation of why it is consistent with EPA regulations.
Dennis
Most people don't give a wit about pollution when they are cussing each other in traffic jams ;-) Seriously though, I think both hybrid and diesel have their places. City seems to be a place for hybrids, which can run on electric alone during slow-moving traffic jams while producing nearly no pollution. The biggest asset diesels have actually is in the inter-state highway driving, where hybrids don't seem to provide much advantage over gasline engine and NOx pollution is not a big deal when the pollutants can be quickly dispersed into the country side. In the city, the accumulation of NOx can be very hazardous to health. In any case, if either or both systems succeed, we will probably see import oil per centage rise again just like it did in the 80's when fuel economy advances drove domestic oil producers out of business.
Other small cars have about the same improvement over the TDIs. Now in this case the TDIs are restricted, but the Landcruisers and Sequoia are not. Now again why are the diesels singled out?
That should not be surprising. Crude oil in its most primordial form is nearly pure hydrocarbon. The sulfer we find in crude oil is often the result of biological (microbial) contamination. Cell membranes and various protein bring in a lot of sulfer and nitrogen. Biodiesel by definition is made from something akin to "contaminants." The same amount of effort put towards purifying biodiesel can almost guarantee produce even purer diesel from crude oil. That being said, the primary attraction of Biodiesel is freedom from big centralized oil distribution infrastructure; that brings in the question of how many acres per car owner does it take to make Biodiesel feasible, and what happens if you need to refuel far away from home (does that mean pump price actually go up because now they serve out-of-towners who are typically less sensitive to local price competition)..
In mid-2006 we will finally see ULSD (15 ppm) available across the USA. At that time diesel cars will be produced with scrubbers and catalytic converters, which currently is not feasible because of the high sulpher content in most of our diesel fuel. So the diesel emissions issue should go away at that time.
I agree with those who say there will be a future for both hybrids and diesels, hybrids being best in congested cities, and diesels being better elsewhere. It will take some time for diesel to overcome the negative opinions of some folks in the USA, but it will happen. Just look at Europe, where clean diesel cars now account for half of all new car sales.
As for oil production here in the US going into a decline, as more efficient hybrids and diesels take to our roads, that would likely be a good thing in the long run. As the world's supply of oil declines to a critical point, being that it is a non-renewable resource, it would be nice to still have some oil reserves available here in the US that we could tap into.
They do in Europe, just not in the US. The reason? Our fuel quality control is garbage. With various base stocks and less QC than Europe, VW (and none of the diesel manufacturers) will let their warranty stand up if used with a high % blend of biodiesel. I believe Cummins says B2 is safe here in the states. Well jeez, with the quality of our fuels here I wouldn't be surprised to find 2% of our diesel is sewage waste.
Why diesel elsewhere?
And where is elsewhere?
Since a clean-diesel that doesn't-require-shifting will cost just a little less than a hybrid and it won't get as good MPG, what exactly will be the appeal factor to make people want to buy one?
JOHN
I disagree with you on the hybrid highway advantage over traditional gas engine. With Atkinson cycle engines, HSD do offer a big advantage over gas-only cars, even better fuel economy than comparable diesel cars. It is easy for Prius to get about 50 mpg at 75mph just by utilizing the cruise control, now with warmer weather.
There is a huge potential for hybrids to further improve efficiency in both ICE and electric sides. Gas ICE has not gone direct injection like diesel had and it is coming to gas engines. There is much more room to improve in energy recapturing(regen braking), energy storage(battery) and energy management system(software). Hybrid improvement in efficiency will lead to higher fuel economy and at the same time, lowering the emission. For diesel, the trade off has to be made between fuel and emission with the use of complex after-treatment emission control systems.
Dennis
I believe, it will take a very long time for a few reasons. In Europe, diesel had a lead start in break thru in lowering emission with after-treatment and high pressure injection from Bosch. Gas is significantly more expensive than diesel in Europe. A combination of those helped the change toward diesel acceptability.
In the US, it is quite the opposite. Diesel technology is behind hybrids by about 9 years(1997-2006). The fuels cost about the same depending on the seasons. By looking at the demands for hybrids in the US today and with upcoming performance hybrids, it will take quite a lot for diesel to catch.
Drivetrain refinement is another issue. Modern diesel engines are just approaching refinement of traditional gas engines in terms of torque curve flatness(no more sling-shot effect). Hybrid like HSD is on another step above in refinement in power responsiveness as well as smooth delivery. Diesel is at disadvantage in idling vibration, noise and emission as well.
Dennis
Now for your current question "Why diesel elsewhere?". First, the VW Jetta TDI gets mileage very close to real-world figures by most Prius drivers, from the many posts that I have read. Both hybrids and diesels get significantly better mileage than gas cars, and so both have promise for the future.
Second, reliability. Diesels are known to last much longer than gasoline cars on average, as has been much reported. There are questions about the durability of hybrids. Just look at the thread "Toyota Prius Owners: Problems & Solutions", posts #2, #4, and #12. Three different Prius owners, all reporting nightmarish
experiences with their cars. And there is still the unanswered question as to durability and replacement cost of battery packs.
Third, price. We see that the Ford Escape hybrid starts about $27,000. The Honda Accord hybrid will be about the same. To get a Prius at this time, many buyers are paying a similar price. Diesels are about $5000 less than this, on average.
It may be that in time hybrids will prove to be reliable. But for now many buyers, myself included, will go for a diesel car.
BOB
Remember, that will be the 10-year anniversary for Prius.
So we have to analysis from that point-of-view, not what things are like today.
JOHN
Yes there are solutions available; however, they do raise the cost of the vehicle.
And since a hybrid like Prius *ALREADY* has that cleansing hardware, its cost won't change. In fact, it will go down due to production volume increases.
By the way, biodiesel is more expensive and less efficient than regular diesel. So there's another problem.
It basically boils down to my original point. An engine-only diesel really doesn't make long-term sense. A hybrid-diesel will end up being a much, much more appealing solution.
JOHN
Since a person couldn't by a Prius right now even if you wanted too (all of them are sold half way through 2005 already), the value of CURRENT doesn't make any sense.
Please explain.
JOHN
I thought I should include this is from message #2 in the Prius Problems Forum. This is backup data questioning the long term viability of the hybrid technology. I have never seen a repair bill on a conventional gas or diesel vehicle that was 3 yeas old for $15k. Something to think about if you plan to keep the vehicle past it's warranty.