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Hybrid vs Diesel
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Say a car can make 200hp from 1,000 rpm to 7,000 rpm. From a stop light idling at 1,000 rpm, the car accelerates from the 1st gear until it reaches 7,000rpm. So, you made 200hp already and get up to a certain speed. Note, the power delivery on 1st gear is very fast but the car speed would probably not exceed 30mph.
Then you skip 2nd gear and switch to the 3rd gear. Now the engine is at 1,000rpm and you make 200 more hp by going up to 7,000rpm. The car would probably get up to 70mph and noticeably reaching to 7krpm takes longer. Therefore, the power delivery is much slower than in 1st gear. The car contains total energy of 400hp which made it get up to 50mph.
You repeat the same in 5th gear and driving at 120mph at 7,000rpm. The car now contain total of 600hp to get up to this speed. Every time you change into higher gear, torque on the wheel gets less and less. But the total possible horsepower you can make is 600hp. If you downshift to 3rd gear, you are limiting the car up to only 400hp(600hp-200hp).
Notice how every time you shift up in gear and start at 1,000rpm, the engine does not have it's maximum power developed yet. But in HSD E-CVT and mechanical CVT, the engine can stay at 7,000RPM and the transmission can adjust to accelerate. That way, engine is at max horsepower all the time. CVT can also put the engine in the RPM that is most efficient or most torque. That's why CVT is superior.
Mechanical CVT achieves this by using belt, cones and pulley. But HSD does it electronically. When you want to downshift(want more torque), Atkinson engine can rev up to max horsepower while MG1 generates electricity. That electricity combined with battery will power 50KW MG2 and provide high torque. Notice how HSD is providing both max hp and max torque at the same time. In traditional transmission, it is either torque or horsepower. This translate to faster power delivery. HSD(Prius) can supply power as fast or faster than ICE only car(Camry) with twice the max hp rating. This also applies for hill climbing which is the reason why this discussion started.
Dennis
What is illogical about that? AC uses electricity and driving on highway takes more energy to push through air so, the mpg will drop. Could it be that you got it the other way around?
Dennis
Turning the A/C on in a diesel doesn't decrease the mileage? That would make diesel-installed A/C miraculous.
The A/C in the new Prius is electric for less draw on the engine.
2014 Mini Cooper (stick shift of course), 2016 Camry hybrid, 2009 Outback Sport 5-spd (keeping the stick alive)
That's terrible!
gagrice, You are correct that a larger, heavier car is safer than a smaller one.
The difference in my view is which works works for my commuter vehicle with only me in it. It doesn't make any sense (to me) to drive...say a large SUV even with an "improved" engine getting...27MPG when I can drive a smaller car with half MSRP and 55-68MPG.
I'm not saying that the smaller car is the only car for everyone...I myself keep a Grand Caravan @ 24MPG to haul 4x8 sheets of whatever and family on long trips. But my GC 24MPG is a joke..but not funny at the pumps. It's almost always parked these days.
I don't personally care for a diesel car.
Thanks
Steve
The only difference between the two cars is that they produce peak power at different engine speeds.
Car A: 200 HP at 2000 rpm (hence 525 lb.-ft at 2000 rpm)
Car B: 200 HP at 6000 rpm (hence 175 lb.-ft at 6000 rpm)
Here is a simple formula you could use to calculate the overall drive ratio (ODR) required to maintain certain wheel speed (in mph) at some engine speed (in rpm), when the wheel diameter (in inch).
ODR = Engine Speed * Wheel Diameter / (336 * Wheel Speed)
Consider an instantaneous wheel speed of 50 mph for both cars. The ODR at that instant for the two cars will be,
Car A: 2000 * 25 / (336 * 50) = 2.976
Car B: 6000 * 25 / (336 * 50) = 8.928
Now, we have two identical cars, with same power (but different rpm due to torque difference) with same wheel speed. You could approximate “thrust” (in g’s) using this formula.
Thrust = torque (including drive train loss) * ODR * 24 / (total weight * wheel diameter)
Calculating thrust for the two cars, at 50 mph (multiplication of torque by 0.85 to assume 15% drive train loss)
Car A: (525 * 0.85) * 2.976 * 24 / (3200 * 25) = 0.40g
Car B: (175 * 0.85) * 8.928 * 24 / (3200 * 25) = 0.40g
Two cars with different torque (525 lb.-ft versus 175 lb.-ft) at same wheel speed (50 mph) have same thrust (0.40g) BECAUSE they have the same power (200 HP). Remember power balances thrust and speed, not one way or the other. You can have more speed with same power, but you would have to give up some thrust. Likewise, you can have more thrust from same power, but you would have to give up some speed.
Diesel seems to give more of an advantage in trucks than in cars...
2014 Mini Cooper (stick shift of course), 2016 Camry hybrid, 2009 Outback Sport 5-spd (keeping the stick alive)
I would have to go along with you on this. Right now the hybrid (Toyota Prius) is a "do it all" machine. There is so much "SEX" about it. (not that anything is wrong with sex) but hey it is the cure for global warming, cure for suvs, the elixir for peace in our time, cure lung disease, cut down oil spills. Shoot even Hollywood types get paid to drive em.
To me when folks like Consumer Reports do their 5 year evaluation and after several recalls etc would be a more reliable judge.
Thanks for your effort by using the formulas and making it so clear. The only way to increase thrust is either increase torque or increase ODR since other numbers are constant. You are right, those two cars can provide the same thrust. The next question is how fast can a drivetrain deliver thrust?
Let's go back to climbing hill genesis. Climbing hill requires extra thrust, agree? Three ways to achieve this goal:
1) Increase torque of the drivetrain
2) Increase ODR(downshift)
3) Do both
In a traditional ICE only car, at full throttle, the engine torque output is static. You can duplicate torque curve by flooring the gas paddle. So, the only way for ICE only car to achieve more thrust is to increase ODR. This means downshift to get more thrust.
Believe it or not, HSD can increase thrust by using #3) Do both. HSD can increase drivetrain troque and increase overall drive ratio(ODR) at the same time! How does it do it? Get a full understanding of Planetary gearset first or you won't understand what I am going to say. First, to increase torque, HSD can tap into battery electric torque instantly. That's the easy part. Second, to increase ODR, MG1(sun gear) will spin backward or acts as a generator. This changes ICE to Driveshaft(wheel) ratio, in another word, increases ODR. Did I mention MG1 is acting as a generator? That electricity will be routed to MG2 to increase more torque as well. Another example of HSD killing two birds with one stone! This is why 76hp Prius can climb hills like a 2.4l 160hp camry.
Dennis
P.S: You may go back and read my previous messages. They might make more sense to you now, why I said, torque is more desire when climbing hill and more speed isn't desire.
"The diesel E320 can get 27 mpg in city driving and 37 mpg on the highway, while the gas-powered E320 gets 19 mpg in the city and 27 mpg on the highway.
However, the E320 CDI cannot be sold in California, Maine, Massachusetts, New York or Vermont, because it violates pollution regulations."
Diesel E320 combined mileage is 32mpg. No where near of Prius. The emission is also night and day.
According to research from TNS Automotive:
What will most likely power vehicles in 2010?
Fuel_______Percent Of Respondents
Gasoline___53%
Hybrid____51%
Electric____26%
Fuel Cells__24%
Hydrogen___21%
Diesel_____16%
Solar______14%
Nuclear____2%
Other______2%
Hmmm... Solar power cars could be as popular as Diesel by 2010. =D
Dennis
__Honda Civic is 5 star rating. Not sure of Prius.
"3yr 36k" (Warranty)
__Yes, this and 5yr/70K battery warrany is the standard for HCH. Since I keep all my cars 10 yrs and 160K miles I got the best extended warranty of 7ry/70K B2B and 10yr/150K on the battery.
"tires that cost double"
__I've not priced the low resistance tires but can also be made with the deal. I've got free tires from the dealer for as long as I own the car.
I'm not out to push an environmental statement, I don't go for the sky is falling global warming hoo-la or the death to us all crowd.
I just want to save some $$ bucks at the pump.
My last tank average was almost 60MPG: more than 710 miles on 13 gallons of gas driving normally with other traffic in a nice comfortable car.
Daily commutes are 58-64MPG day after day.
Given these figures it wouldn't make sence to drive daily commutes in a truck that gets only mid 40's MPG and have to put up with the hastles of diesel, or a VW TDI getting only 50MPG.
It will be interesting to see in 10 years what will or won't be available in either or both technologies.
Thanks
Steve
Diesel E320 combined mileage is 32mpg. No where near of Prius
And Prius' doesn't perform anywhere close to the diesel E320. As much as I'm eager to see hybrid technology mature, I try to appreciate things as they are. And new diesels can definitely stand on their own.
In a recent test, diesel hybrid (2.2 liter I-4 i-CTD, 140 HP/250 lb.-ft) returned 92 mpg (mixed driving). Even if this is in imperial gallon, it is still impressive (also given the performance). I wonder how much improvement (fuel economy and emissions) hybridizing this diesel could bring.
Daily commutes are 58-64MPG day after day.
Given these figures it wouldn't make sence to drive daily commutes in a truck that gets only mid 40's MPG and have to put up with the hastles of diesel, or a VW TDI getting only 50MPG.
It will be interesting to see in 10 years what will or won't be available in either or both technologies.
Thanks
Steve "
Since you have a gas/hybrid, it will be interesting to see your long term history 100/200/300/400/500 K miles. One other thing I would be interesting in knowing is; other than the normal unscheduled maintenance stuff, what your battery replacements costs will actually be. So the real question is it worth your up front premium (4k) to drive a gas hybrid and down stream battery costs (local rag mentioned 3k).
Actually, you seem to be a very fuel efficiency minded driver. I have heard of Jetta TDI'ers pushing 60-65 mpg. It would be interesting to see what you can do with it, despite your bias. I have driven the Prius for 5 hrs but did not do a full tank refill. Magazine tests report 40-45 mpg. This is a lot less than its 51 highway and 60 city mileage epa.
The thing I really like about the TDI is you really don't have to be very care "fuel efficiency" wise. Yesterday and today, we made two round trips to the exact same destination 162 miles R/T x 2 days, "freeway town and country) 2 hrs each way one day, (obviously heavy COMMUTE bumper to bumper traffic) and this morning 45-50 min . Filled up and got 48 mpg. Loaded with 4 people, with the AC ON!
As you know diesel is more efficient than unleaded gas, app 37%. So a diesel hybrid mating would be "better."
Gasoline___53%
Hybrid____51%
Electric____26%
Fuel Cells__24%
Hydrogen___21%
Diesel_____16%
Solar______14%
Nuclear____2%
Other______2%<<
Uh, aren't all the numbers supposed to add up to 100%?
Anyway, let me add mine here. If diesels were available in California, I would be driving one.
___In regards to the latest Honda designed 2.2 L iCDTi Diesel Performance, Fuel economy, longevity, and drivability concerns may have disappeared. With an even smaller 1.0 - 1.3 L in a Civic/Insight (non-Hybrid format), you are probably looking at meeting Euro V emission specs which are every bit as tough as ULEV here in the states. Can anyone possibly not see an advantage to cheaper to purchase and cheaper to own then any hybrid to date?
___The new iCDTi Accord diesel 0 - 62 in 9.2 to 9.3 seconds in a > 3,000 # automobile and meets Euro Spec IV specs. That is anywhere between TLEV and SULEV depending on what is being measured:
___Here is the rundown in terms of CO, HC, NOx, and PM in grams/mile
TLEV:*3.4****0.125****0.400****0.400
LEV:**3.4****0.075****0.050****0.010
ULEV:*1.7****0.040****0.050****0.010
SULEV:1.0****0.010****0.020****0.010
Euro IV:0.50****0.010****0.250****0.025
Euro V:0.50****0.040****0.080****0.010 possibly?
___And the Accord Diesel beats Euro IV while breaking world records of many types as the Vtec link shows.
___Finally, a few more accolades as stolen from a Vtec member known as BMC:
http://www.vtec.net/forums/one-message?message%5fid=234672&ne- ws%5fitem%5fid=234399
QUOTES FROM THE UK PRESS ABOUT THE ACCORD DIESEL!
“I’d defy any passenger not
already ‘primed’ to even notice
this was a diesel engine.”
Top Gear, test drive Dec 2003
“It delivers strong, real-world
performance with a new standard
of diesel refinement.”
“Stunning engine, fine car.”
Autocar, 11/03
"It was one of the most harmonious,
most complete drives I've had all
year. It just gelled"
Evo, 11/03
“Seems Honda has got just about
everything right first time.”
Autocar, 09/03
“Smoothest and most refined in class.”
Fleet Week, 7/03
“Superbly quiet and smooth.”
“The Accord diesel is one of the
most refined around.”
What Car? 10/03
“It works, brilliantly. No, it is
better than that: it is easily the
smoothest, most refined, least
dieselly diesel I have driven ”
The Independent, 09/03
“This vehicle even behaves like
a petrol, making Volkswagen’s
laggy PD TDI 130 feel dated.”
Auto Express, 08/03
“This feels like the new
benchmark for four-cylinder
diesel refinement.”
Car, 10/03
___Good Luck
___Wayne R. Gerdes
I also favor more horsepower. But power delivery rate(thrust with time) is also important. So, you should also look at thrust to weight ratio across a range of speed. Prius has better thrust/weight ratio than 2.4l camry from about 30mph to 50mph. Camry has better thrust/weight ratio from about 70mph to 100mph. If you are climbing hills at around 40mph, Prius might do a better job. If you climb hills at 70 or 80mph then, Camry will have the advantage. I hope that explains where power delivery rate shines and more horsepower shines.
Traditional ICE only cars are bloated with horsepower. The reason is to achieve faster power output rate. Again, if a hybrid drive train double the power delivery rate, we will have to redefine how much horsepower we actually need to achieve the most difficult driving tasks with higher power output rate.
I am also curious how a hybrid diesel would synergize. I mean, the two are pretty similar in power output. High torque at low rpm but low horsepower. The cause of diesel low hp is due to low achievable RPM. For electric, low hp is due to low torque at high RPM. Maybe there is a design can unite the two natures and create a synergy effect like current gas electric HSD.
I read about Toyota traded HSD license with diesel patents from Ford. I am sure Toyota is toying around with diesel electric for cars. There are Toyota diesel electric trucks in Japan. I believe they are serial hybrid design. Maybe, those Ford diesel patents might give us some clue.
Dennis
Those diesel emission numbers are impressive. They really need to work on NOx though. For reference, in 1997, the classic Prius was first to comfortably meet EURO IV, J-ULEV and AT-PZEV emission regulations at the same time. 2004 Prius beats it by far.
Dennis
P.S: Nevermind, i found your other post.
I'm not sure I could have typed that with a straight face. C'mon, who in the world wants to compare an E-class benz with a Prius?? We're talking a big heavy luxury car that can average 32mpg and perform on-par with vehicles that average 10mpg less. When they can get the prius to accelerate from 0-60 in 6.5 seconds (or any other performance range you want) and still get 40,50,60mpg then we can start comparing the two. Even without all-wheel drive, the E-320 CRD is very close to replacing my A6 4.2 that's lucky to eek out 20mpg.
Traditional ICE only cars are bloated with horsepower.
Not sure what you mean by that, but your assumptions regarding horsepower are bad. And no matter waht you want to calculate (power to ratio, g's (that I already did to show you how it relates to horsepower) etc., power rules. Peak power? No, but mean power developed across the board. More power, better performance, that is the bottom line.
And apparently we'll also have nuclear powered cars by 2010, too? I can't put any faith in research that shows a nuclear powered vehicle will be on the road in less than 6 years. Do 14% of people actually think that solar power will "most likely" propel vehicles in 2010? wow. Who did they survey?
Emissions are not night and day. There is 1 component preventing them from being sold in eco-states and that is sulphur. US diesel fuel needs to catch up with Europe in sulphur content and that will happen in 2006.
Plus you're comparing the mpg of a powerful Mercedes with a Prius. apples vs. oranges. Try comparing hybrid to diesel when the 2 cars have similar performance. I could make the same analogy comparing a Prius to a moped. Makes the Prius seem like a gas guzzler.
I'm only defending truth and a fair comparison here. I think there's room for both. Kudos to people who drive the Prius. I can't. I need AWD where I live. I care about what a car looks like (and IMHO, the Prius is butt-ugly). I need a practical car, which means (in part) that I have to be able to do the work on it myself.
Exactly. Someone posted a review of E320 which compare mpg to Prius and claimed that diesel E320 can get the same fuel economy as Prius. First I pointed out that E320 is twice expensive. That response was to show the real mpg numbers. Please read previous messages to get the whole picture.
Dennis
And, furthermore, even toyota says that most users can't expect to get the EPA figures, and several reviewers have gotten significantly better than the E320's EPA numbers, so much so that observed mileage has been the same. I just think that's awfully impressive.
"Even without all-wheel drive, the E-320 CRD is very close to replacing my A6 4.2 that's lucky to eek out 20mpg. "
Envy, envy.
dave
No, I'll highlight the important part that you missed. In 1997, the classic Prius was first to comfortably meet EURO IV, J-ULEV and AT-PZEV emission regulations at the same time. HCH might be the fist to meet AT-PZEV but might or might not meet Japanese and Europe emission standards.
Dennis
Well check out the whole article. http://www.motortrend.com/features/news/112_news006/
Dennis
There are Prius drivers with light foot on gas got about 80MPG. Also, it is not fair to compare Prius winter mpg to warmer spring E320 CDI mpg. E320 diesel's combined 32mpg isn't impressive if you look at RX400h combined 34.5mpg. HSD will have superior response and mid range power delivery than diesel. Only if they make a diesel hybrid that boosts passing power......
Dennis
Plus the question can be taken a number of different ways.
"What will most likely power vehicles in 2010?" can mean:
1. Based on 2010 car sales, cars with which fuel will sell the most?
2. Which fuels will be available to power vehicles?
3. Of the cars on the road in 2010, which fuel will be the most prominent?
Dennis
I believe that the E320 review listed real world mileage, whereas the RX400h is a hypothetical release of EPA by Toyota. I bet the RX gets less than the E320 under normal useage.
"it will be interesting to see your long term history"
__I keep my all my cars 10 years, at that time I'll have about 160km. I had the same concerns so I bought the highest warranty of 7yr/70K b2b & 10yr/150k battery. Battery technology $$ generally go down.
I paid about 3.5K over its sister Civic EX, which is not nearly as nice.
"I have driven the Prius"
__I've not driven one either. Toyota didn't have one. Rick Reese an Insight gamer has one and gets around 80MPG.
Admitted this is not the "norm" and neither is my HCH MPG. Only a few folks play this game.
"It would be interesting to see what you can do with it" (diesel)
__Thanks. Give any gamer an accruate clear to read FCD and you'll see great results no matter what fuel. (Gas, diesel, nuclear, anti-matter etc)
Wayne, Rick and others are good enough not to require FCD. I still need one.
gagrice:
"Does it require Premium Unleaded as the Prius does?"
__HCH burns regular (not)leaded 87 octane fuel.
I'd HATE to pump in those extra $$.
"I will be interested to see your long term impression of the hybrid civic."
___Me too! So far I rate it 9 out of 10 "stars".
2. Fuel costs are whatever the price of gal of fuel/ 45-60 mph.
3. In my case, I am right around .06 cents per mile total operating costs.
My projected time to hit 100 k miles or 160 km is 3.5 3.8 years.
Oil, oil filter and tires are covered by the dealer for as long as I own the vehicle.
HCH has a real-to-God chain, not belt.
Not sure what my average CPM would be.
I do know that I won't be getting any speeding tickets bumping up insurance! :-)
Steve
Diesel makes more sense to me than hybrid at this time when comparing cost and available features and performance.
I suppose the question is, why isn't VW promoting it more?
I agree about ESP. I wouldn't get a car without it. You might not use it for 20 years, then it'll save your life.
The base jetta/golf aren't particularly cheap, but they are full-featured ( abs, heated mirrors, side airbags, etc) , have superb safety, and drive like much more expensive vehicles.
dave
Dennis
My neighbors have been looking for a wagon and it look like they're going to have to place an order. No dealers within 200 miles have any in stock.
My brother has a newer 6.0L Ford and we had a little race between it and my Tahoe. I was about two car lengths on him until about 50mph, then he shot passed me like I was barely moving. He's driving a 1500# heavier vehicle as well.
I think if we were talking normally aspirated diesel motors, usbseawolf2000 might have a point. But once the turbo winds up, these diesels do a mighty fine job.
Simply, the above quote might be arm chair analysis.