By accessing this website, you acknowledge that Edmunds and its third party business partners may use cookies, pixels, and similar technologies to collect information about you and your interactions with the website as described in our
Privacy Statement, and you agree that your use of the website is subject to our
Visitor Agreement.
Comments
How, exactly, would one duplicate what a hybrid can do in a diesel?
1. In regards to AutoStop, in a diesel, you would do what? Manually kill the engine and restart it at every red light or stop sign? That would be wasting fuel, because stopping and restarting a typical diesel engine uses fuel, whereas in a hybrid, NO fuel is used when restarting the engine with the AutoStop feature.
2. Do you put the diesel car into neutral and coast when you get a chance? That's what hybrid hypermilers do.
What other "tricks" can diesels do? :shades:
You have not posted any links that give the emissions of the lower sulfur fuel that is already mandated in CA. Also at 62 MPG I am sure the TDI emits less CO2 than the hybrids at 50 MPG. And the hybrids do for sure emit more CO than the TDI. With low sulfur fuel the PM is probably comparable. That leaves only NOx to haggle about. It is an unknown until someone comes up with data on the TDI using ULSD. A VW TDI is still a lot cleaner than most cars that are 5 years old on the road today. Including Honda and Toyota cars.
Hybrids are a new, different technology, and they require new, different attitudes about how to drive efficiently. It's not the "same old same old" anymore.
If someone comes out with a CLEAN (legal in 50 states) 5-passenger diesel/electric hybrid sedan rating 60+ MPG combined EPA, I will be the first in line.
Until then, gas hybrids are the best we got.
You know as well as I do that the diesel proponents will be ALL OVER a result like that.
If it happens, it wont be hard to find the clamoring horde propelling the info to and fro. :shades:
I think truly this is where we disagree in that you have not driven a diesel. As you know, but probably haven't posted, the Prius has a behavioral modification tool which in effect has not much to do with the hybrid, but at the same time has EVERYTHING to do with the hybrid. I think they might have put it in because it is qualitatively and quantitatively harder to drive a hybrid. (for mph) So if the behavioral modification tool is used on a diesel, it would be even easier to drive (for mph) for a diesel.
The other thing that is a tad bit apples to oranges is the TDI gets great mileage with a far bigger engine, and less hp than a Prius. So in effect if the diesel had the same sized diesel engine as the Prius, the mpg would be even better.
Basically, it's the same mechanism behind SUVs becoming popular among people who don't benefit from their traits. Buying something that reflects your personality and you'd like to be seen in. According to the research these guys did, most of the people who buy hybrids don't even consider their non-hybrid counterparts, and gave the costs only secondary consideration. Not a new idea in these forums, but I thought I'd share (it was linked on FourSprung).
Another concern is that putting the trans in neutral while coasting is dangerous. It can get you killed in an emergency situation.
Remember emissions technology has been an evolving item on gassers since the late 1960's, so you have a 30+ year head start. It appears that you expect that diesels have their emissions technology evolve in five minutes. I feel that the technology for diesel emissions will evolve more quickly than for gassers.
I drive a diesel and would like to see it cleaner. If any technology comes along that I can retrofit on my CRD for a reasonable price, I will do it.
The Prius, like the HCH and the Silverado/Sierra hybrid pickups, uses a device called a "Integrated Starter Generator" which is not a traditional starter.
An "Integrated Starter Generator" (ISG) replaces the starter and alternator, and allows the gasoline engine to shut off during idling. This technology improves fuel economy by using the stored energy of the hybrid battery to restart the engine after AutoStop has been engaged.
Sure, fuel is used once the engine is STARTED, but the ACTION of starting the engine uses no fuel. The ISG shuts off the IC engine when it’s not needed, then quickly restarts the IC engine when power is required.
An electric motor-generator device replaces the standard starter and alternator. It’s wired to batteries that store energy. Since the motor-generator device does not help propel the vehicle, a conventional gasoline engine handles that job unaided.
Since the motor-generator is far more powerful than a conventional starter, it quickly and easily wakes up the sleeping engine when the accelerator is tapped after the stoplight turns green.
Conventional engines are started by a starter, which simply rotates the engine while fuel is injected and spark plugs fire; unless the engine is rotated, the engine won't start. The Prius uses the electric motor to get the car moving, and then the gas motor starts the same way, only it doesn't need fuel to start, because it'll start by virtue of the stored power in the hybrid battery.
As to engine rotation, no engine will start unless it is turned over and no engine catches immediately, be it gas or diesel. It takes a number of revolutions at a certain minimum speed for an engine to start. It may take several Otto cycles (Atkinson in the case of the Prius) before an engine catches.
The gas motor starts the same way, only it doesn't need fuel to start is a rather strange statement. If you do not put fuel into the engine, how will it start? The battery and starting device can crank the engine until the cows come home, but no fuel no start. :confuse:
Today reporter compared a Toyota Prius hybrid with a Volkswagen Jetta diesel,
The article in question is erroneous in many ways but does make some good points about adjusting the way most people drive in order to conserve fuel.
The USA Today test.. discussed here previously is at best anecdotal, hardly scientific because the conditions were not parallel nor done at the same time. He drove one way in one vehicle and back in a different one. Do you seriously think this is a valid test? Drive both together with two drivers alternating every two hours on the full RT from Ann Arbor to DC and back. That's a valid comparo.
The Vancouver BC autodrive test with 5 vehicles at the same time over exactly the same route is a better comparison. But you knew that.
This one is even better:
http://www.caranddriver.com/article.asp?section_id=15&article_id=8427
Welfare for the wealthy?
Pullleeze... It's the average Joe who will benefit the most by the tax credit. The wealthy will normally not be able to take it due to the AMT.
The conclusion of this particular article in this particular paper is just a way to appeal to the prejudices and anger of those who may have some valid skeptcism or not be able to take advantage of the credit this year. Pit the blue-collar-Joes against the 'wealthy-welfare-recipients'.
Doing this does nothing to improve our society. It's low and based on false premises - muckraking at it's finest. But that little detail was of no interest to the writer I'm certain. Did he refer to the C&D comparo for balance. No.
Is this the type of in-depth analysis you use in your daily life. I don't think so from your well-thought-out positions in favor of alternate fuels.
This is false.
When I give no concern to fuel miserliness in a diesel, I get what a hybrid gets. When I drive like a fuel miser in a diesel, I can easily get 62 mpg.
In slow-moving traffic or on a typical 'Sunday drive' getting 65-90 mpg is commonplace.
This is of course at app 7500 less acquisition cost.
The acquisition cost is a very subjective point. It goes to different wants and tastes. There is no valid way to compare your preference for the Jetta's handling vs my preference for room and comfort.
Unless you got your Jetta for < $15K the $7500 figure is too high.
I drive all day @ 58-63 mph with no special effort in any manner and get 48-49 mpg - in winter. We probably each accomplish the same thing with the same lack of effort in vehicles which suit us individually.
Your Jetta is good for you and my Prius is good for me. Life is good.
I am not sure why you say it is false when your results agree with mine. If I drove all day at 58-63 mph with no special effort in any manner, I can get upwards of 55 mpg. I did a measured 80 mph and got 52 mpg.
Also perhaps your perception of subjective is FAR different than mine. It is not very "subjective" when folks ask for and get a price and you have a contract with a seller. When friend's of mine agrees to pay 25 and 29k for eachs' Prius and I agree to pay 18k (7-11,000 difference but who is counting) this is NOT subjective!!?? So if you think it is, then I would submit you and I have far different perceptions of "subjective"
So using your venacular, of subjective use of 11,000, I can buy @2.69 per gal 4089 gals of diesel fuel. With 50 mpg that subjectively is app 204,461 commute miles. At 19k miles per year that is subjectively 10.76 years of commuting.
But I do have to agree, Life is good.
In the HSD, unless you stomp on the accelerator, you overcome inertia initially by the drive of the high-torque electric motor ( MG2 ) while the smaller motor (MG1) starts the ICE spinning as if it were already in it's more efficient phase, fuel is added at this point when the ICE is working more efficiently but it's less fuel than if the ICE had to start the vehicle moving by itself.
Here is a good basic comparison between a Hybrid gasser and a conventional gasser.
Both vehicles are essentially ICE gassers. However,
in optimal city driving the Hybrid system allows the ICE to shut down about 50% of the time;
in optimal highway driving the Hybrid system allows the ICE to shutdown about 20% of the time.
Your specific combination of city/hwy driving will determine the weighted average of your particular FE. Most drivers are finding that this weighted average is ~ 30%. YMMV.
However might I draw your attention to:
"The EPA testifies that the Civic hybrid gets 49 mpg in city driving and 51 on the highway. But those numbers are rarely achieved. To get mileage in the high-40-mpg range requires gradual acceleration, timid cruising speeds, and cautious use of the throttle. Suffer a short lapse in concentration or accelerate immoderately, and fuel economy will suffer. Fact is, to do this right, you will drive more slowly than you ever have."...
http://www.caranddriver.com/article.asp?section_id=3&article_id=10393
So evidently this team of august testers would find your assertion/s false, despite the Honda Civic taking first place in the comparo.
A Prius can be obtained for $22-23K. But this is why it's subjective. Your two friends voluntarily chose vehicles which suited them. I chose voluntarily to pay a price in the $20K+ range because I wanted the room and ride similar to my past vehicles. A smaller, even less expensive vehicle was ruled out immediately.
Why does one pay $35K+ for a Lexus vs $17K for a Corolla. Because they want to. It's entirely subjective. Price is not an issue really. Your choice is just as valid as mine.
Trust me it is not I that questions validity of choice. If anything I believe in market choice!, choice!, choice!.
This is certainly valid because it's apples/apples if your only consideration is fuel savings recovery. I agree. If you also have the interest to drive a less polluting vehicle then the equation is murkier because of the subjectivity issue.
C&D's statement is probably correct ".. you will drive more slowly than you ever have." In driving one you do find that driving the normal speed limits gives you the best FE. Most people, myself included, drive somewhat over the speed limits. The EPA's test is based on the speed limits. If you replicate the EPA's conditions you will achieve their FE ratings as well. Nothing new here.
So evidently this team of august testers finds your assertion false, despite the Honda Civic taking first place in the comparo
Run that conclusion by me again? Which asseretion?
Then you say getting less mileage when you don't is "nothing new".
You give Former President Clinton a run for his linguistical money.
I only drive vehicles that meet with the emissions laws of the land, as do most folks. And even if I did not, the periodic smog tests probably would end their operation.
So in a plain vanilla daily commute of 50 miles R/T, the Honda Civic makes a whole lot of sense.
I think a lot of the mileage problems are a result of location. If you live where driving slow is not a problem the Hybrids may be just the ticket. The Western US has a lot of 75 MPH travelers. Or very slow stop n go commuting. Or they may be like me, where most of my trips are under 3 miles at 35-45 MPH. Unless I get on the freeway then 75 MPH is the norm. I lost interest in owning a hybrid when it came out that the mileage varied so radically as a result of driving habits. I was used to 13 MPG year round in the Suburban. All these things have to be taken into consideration before jumping into a hybrid hoping for the 60 MPG in the city. I doubt that 2% of Prius owners get 60 MPG for a tankful of gas. On the very popular website for hybrids out of 455 Prius II owners posting, only 5% get the EPA 55 MPG or better. So when a writer states that most hybrid owners are NOT getting EPA and many are unhappy about it he is being truthful. A full third of the posters are getting 45 MPG or less. We can thank an EPA that bows to the pressures of the automakers.
Agreed about most drivers getting less than EPA. That's factual and verifiable as you stated. However I'm not so sure about these drivers mostly being unhappy about it. That is an opinion and not verifiable without interviewing most. IMO, and it is an opinion, the Prius drivers reporting on this website are honest in their opinions in that they could achieve EPA ratings, if they had the perfect conditions to do so. Most drivers dont, it's winter, they drive too fast by necessity, they have too many short trips, etc.
Using the EPA as a barometer is OK, if you understand the conditions, but in real world driving the overall result is that the vehicle gets about 48 mpg combined, possibly a little higher.
The EPA's 55 combined is an artificial composite that 50% of driving will be at city and 50% at Hwy. The more highway you drive the more your weighted average will approach the Highway number of 51. Now this is consistent with the reported actual numbers. This is my understanding of what is occcuring.
I really have no interest in "slamming" folks.
So given the current technology, one has to know how, etc to DRIVE the technology. This gets down to not pushing the gasoline engine into the uneconomical zones and then driving the hybrid portion so it is on rather than using fuel.
I'll give you that one as tough to verify. I think I have seen more posters with RX400h complaining than Prius owners. I guess the more you spend the more you expect.
What?
Really?
Without knowing a whole lot about HSD technology, I can guarantee that this kind of fuel mileage is impossible for a anybody except Wayne and people with similar skills.
Hardly commonplace.
The MFD showed one 5 min segment @ 40 mpg 6-7 segments in the 50+ mpg range; 3 segments in the 70+ mpg range; and one in the 90+ mpg range. I did nothing but drive using no special strategies. SOTP average for 50 mi was 62-66 mpg. If this was my daily commute, rather than 130 mi @ 60 mph and 20 mi in the city I can see where 55-65 mpg is easily attainable on average, with some extraordinary spikes like 90+.
This is why I can say with 100% certainty that the EPA ratings are attainable if your specific conditions permit.
Excellent point. There is a site that gathers this info and graphs it statistically; mean, median, std dev, etc.
This is why I can say with 100% certainty that the EPA ratings are attainable if your specific conditions permit.
You are a car dealer. Please talk with some credibility. There is no such thing as SOTP fuel mileage. And I don't care about the display. Fill up your tank a few times and then calculate mileage.
If you think driving 50 miles at 25-40 mph was "commonplace" you must have a very tiresome and boring commute.
I have probably done 50 miles in that kind of speed maybe 5 times in over 10 years of driving.
I have only taken one drive like that in 47 years of driving. It is the 55 miles from Kihei, Maui to Hana, Maui. It is a looooong 3-4 hour drive. So maybe that is what the Prius is ideally suited for. I cannot think of a 50 mile "A" to "B" trip in the West that would fit that criteria. The Prii I encounter in San Diego are going with the flow, 70-75 MPH. I imagine they are part of the majority that are getting 45 MPG average. Not too shabby, just not enough for me to consider the Prius.
Did you see the segments I posted? This was for a 50 mi RT sunday drive as I stated. Now do an average of the segments and you get......... ~ 62-65 mpg. easy.. basic.
SOTP because with the Prius you can only pull out short trips within a tank by recording the individual segments and averaging them. If I had foreseen what the drive was going to be I would have zero'd the trip computer and gotten a more precise average. But it was my wife who noted the high values and started noting them down.
This anecdotal experience conforms to what those who are reporting high FE ratings are stating. Since I've done it once I am certain that it can be replicated. It wasnt magic that it happened it's just physics. Drive a certain way and the result will flow naturally.
As I've stated many times here my normal commute presently is 150 mi/day RT with ~130 mi highway and 20 mi or so local. Over the 2 month life of the vehicle and 5300 mi I'm averaging just under 48 mpg after the 1st 1000 mi breakin period ( 43 mpg ).
Now about driving 40000+ annually on a commute. I've done it for 25 years.!! the first 20 years or so were commuting into NYC from No Jersey during rush hours. 30 mi in 75 min ( that's 24 mi/h ) at the quickest or 3 hours ( that's 10 mi/h ) at the worst. Now what were you saying about a boring commute. Side note: In the last 25 yrs I've never lived and worked in the same state at any time. My daily commute has always been to a different state.
Now my oldest son is really nuts. His daily commute is 330 mi RT into NYC. - but it's by train.
Be skeptical if you want. You'll be wrong but it's your right.
In my test drive, I did not do any serious stop and go driving per se. The ICE did shutdown at a light and came to life again at about 25 mph. On the highway, the ICE never shut off and the rpms seemed constant at cruising speed. I always found the transition harsh and abrupt from electric to ICE, no matter how gentle I was with the right foot.
I'm somewhat surprised about your feeling on the 'harsh transition'. IMO it's noticable but it's less so than a normal geared vehicled during shifting.
One 'trick' if you will to better utilize the HSD system on highway driving goes to your comment about the ICE never shutting down while driving on the highway. The P&G does work in shutting off the ICE while maintaining speed. If you accelerate to 70 mph for example and let off the pedal the electric motor will carry you a good distance, especially on flats and down hill, at current speed without slowing dramatically. If you do slow down to 65 for you may have travelled a half mile or so on no fuel. Accelerate up to 70 again and repeat. Most efficiently the ICE could shut down for as much as 20% of the distance.
I do not drive a Prius but drive a Jeep Liberty CRD. On the highway at 65 mph, the transmission seems to partially disengage during coasting on flat surfaces and downhill. The rpms on the tach also drop by several hundred, but the engine never returns to idle speed. In my experience with the Prius, I did coast some on flat straight aways (easy to do in FL) but the engine speed did not seem to change. I actually took my foot off of the pedal and the car started to slow down a little. The engine did not shutdown or return to idle. I had the cruise control on so that may explain some of what I observed.
Yes this is precisely the situation. With cruise on whenever the speed slows slightly the fuel is injected right away. It cancels out the use of the P&G driving.. and the benefits.
There is nothing ina hybrid that will freeze up any different than a non-hybrid car, unless you know something I dont know.
I know we have owners in Minnesota and probably in AK too, but I have never heard of a hybrid being disabled by cold weather.
I thought maybe someone from a real cold place like the Yukon or Fairbanks would give us some insight.
Is your statement humor? If not, tell us about failed turbos and transmissions and overheating. And I'm talking about proof, not propaganda!
There has been no overheating of CRD's. There was a software issue that caused an incorrect reading on the temp. gauge of some CRD's. Yep, it is not just Prius that has software problems.
I believe in both!
(Hooray for moderation)
They both have many desirable qualities. Diesels are nice because they get outrageous (in a good way) amounts of torque and good gas mileage. If I were to get an SUV, it would be a diesel over a hybrid. Also, diesels are possibly more conventional than hybrids.
Hybrids have a less conventional powertrain and would therefore cost more to service. They would get better gas mileage than diesels but they would be less powerful. Probably better in cars.
""Notwithstanding wild claims that Dubya has 'destroyed the environment""
Wild claims, eh? *displys prudence and shuts mouth* :P
Darn. Couldn't help it.
Read the posts in the Prius Problems Forum. Not flattering.
Is the above an accurate picture of Prius reliability?
http://www.timesofmalta.com/core/article.php?id=213097